Communication method, apparatus and system for multiple access points

ABSTRACT

Embodiments of the present invention provide a communication method, apparatus and system for multiple access points. The method includes: simultaneously sending, by a primary sending terminal and a secondary sending terminal, data corresponding to each receiving terminal to each receiving terminal through a shared channel; sending, by the primary sending terminal, BAR corresponding to the data to each receiving terminal; receiving, by the primary sending terminal, BA corresponding to the BAR and sent by each receiving terminal; and if the BA indicates that the data are correctly received by each receiving terminal, clearing the data cached in the primary sending terminal, and if the BA indicates that the data is not correctly received by each receiving terminal, retransmitting data which is not correctly received, and clearing correctly received data cached in the primary sending terminal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2013/080751, filed on Aug. 2, 2013, which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a field of communication, andparticularly, to a communication method, apparatus and system formultiple access points.

BACKGROUND

In a wireless communication system, multiple input multiple output(MIMO) refers to construction of multidimensional space resources byusing multiple antennas. Multiple parallel paths are formed by thesemultidimensional space resources. Thus, a wireless station in the systemmay use these parallel paths to transmit multiple paths of signals toimprove a rate of data transmission. Generally, it is called downlinkmultiuser multiple input multiple output (DL MU-MIMO) for a manner thatone wireless station configured with a larger antenna numberdistinguishes users and transmits data to multiple wireless stationsconfigured with smaller antenna numbers using space resource, and it iscalled uplink multiuser multiple input multiple output (UL MU-MIMO) fora manner that multiple wireless stations configured with smaller antennanumbers distinguish users and transmit data to one wireless stationconfigured with a larger antenna number using space resource.

In the prior art, in a wireless communication system which obtains achannel based on a way of competition, in order to guarantee thereliability of data transmission, in DL MU-MIMO, a sending terminal,after data is sent, needs to inquire a condition of data receiving ofeach receiving terminal one by one according to a certain time sequence,since multiple receiving terminals are provided. After the eachreceiving terminal receives the inquiry, the receiving terminal returns,if data are correctly received, information about the data is correctlyreceived to the sending terminal. In UL MU-MIMO, after multiple sendingterminals simultaneously send data to a receiving terminal, thereceiving terminal returns, if the data are correctly received,information about the data is correctly received to the each sendingterminal one by one according to a certain time sequence, or thereceiving terminal only returns one piece of information about the datais correctly received. However, in this information, each receivingterminal needs to be instructed respectively.

However, the above-mentioned two scenarios merely support error recovery(retransmitting data which is not correctly received by a receivingterminal) for data transmissions between one sending terminal andmultiple receiving terminals in DL MU-MIMO and between multiple sendingterminals and one receiving terminal in UL MU-MIMO respectively.However, error recovery for transmitting data simultaneously betweenmultiple sending terminals and multiple receiving terminals is notsupported. Thus, for a system transmitting data between multiple sendingterminals and multiple receiving terminals simultaneously, reliabilityof the data transmission cannot be guaranteed.

SUMMARY

An embodiment of the present invention provide a communication method,apparatus and system for multiple access points, which can support errorrecovery when multiple sending terminals and multiple receivingterminals transmit data simultaneously, so as to guarantee reliabilityof data transmission and improve throughput of system.

To achieve an above-mentioned objective, an embodiment of the presentinvention adopts a following technical solution.

In a first aspect, an embodiment of the present invention provide acommunication system, including a primary sending terminal, at least onesecondary sending terminal sharing a channel with the primary sendingterminal and at least one receiving terminal, wherein,

the primary sending terminal is configured to:

respectively send data corresponding to the each receiving terminal tothe each receiving terminal;

respectively send a block acknowledgement request BAR corresponding tothe data to the each receiving terminal;

receive a block acknowledgement BA corresponding to the BAR and sent bythe each receiving terminal respectively; and

if the BA indicates that the data are correctly received by the eachreceiving terminal, clear the data cached in the primary sendingterminal, and if the BA indicates that the data are not correctlyreceived by the each receiving terminal, retransmit the data which arenot correctly received, and clear correctly received data cached in theprimary sending terminal;

the secondary sending terminal is configured to:

simultaneously send the data to the each receiving terminal with theprimary sending terminal through a shared channel; and

the receiving terminal is configured to:

receive the data sent by the primary sending terminal and the secondarysending terminal;

receive the BAR corresponding to the data and sent by the primarysending terminal; and

send the BA corresponding to the BAR to the primary sending terminal.

In a first possible implementation manner of the first aspect,

the secondary sending terminal is further configured to:

obtain the BA sent by the each receiving terminal through the sharedchannel respectively; and

if the BA indicates that the data are correctly received by the eachreceiving terminal respectively, clear the data cached in the secondarysending terminal, or if the BA indicates that the data are not correctlyreceived by the each receiving terminal, simultaneously retransmit datawhich are not correctly received with the primary sending terminalthrough the shared channel respectively, and clear correctly receiveddata cached in the secondary sending terminal.

In combination with the foregoing first aspect or the first possibleimplementation manner of the first aspect, in a second possibleimplementation manner,

after respectively sending the BAR corresponding to the data to the eachreceiving terminal, the primary sending terminal is further configuredto resend, if not receiving the BA corresponding to the BAR after apreset time, the BAR to each receiving terminal which does not sendsback the BA.

In combination with the foregoing first aspect or the first possibleimplementation manner of the first aspect, in a third possibleimplementation manner,

after receiving the BA sent by the each receiving terminal respectively,the primary sending terminal is further configured to send, if the BAindicates that the data are not correctly received by the each receivingterminal, a data indication to the each receiving terminal not correctlyreceiving the data, wherein the data indication is used for indicatingdata which are not correctly received by the each receiving terminal.

In combination with the foregoing first aspect or any implementationmanner from the first possible implementation manner to the thirdpossible implementation manner of the first aspect, in a fourth possibleimplementation manner, there are more than two receiving terminals,

the primary sending terminal is specifically configured to respectivelysend the BAR to the each receiving terminal according to a presetsequence, wherein the preset sequence is that sending the BAR to eachreceiving terminal belonging to a same basic service set BSS as theprimary sending terminal at first and then sending the BAR to eachreceiving terminal not belonging to the same BSS as the primary sendingterminal.

In combination with the foregoing first aspect or any implementationmanner from the first possible implementation manner to the fourthpossible implementation manner of the first aspect, in a fifth possibleimplementation manner,

the primary sending terminal is specifically configured to:

obtain a first indication according to the BA, wherein the firstindication is used for indicating the data correctly received by theeach receiving terminal, which is obtained by the primary sendingterminal; and

clear, according to the first indication, the data corresponding to thefirst indication, which is cached in the primary sending terminal.

In combination with the fifth possible implementation manner of thefirst aspect, in a sixth possible implementation manner,

the primary sending terminal is further configured to send the firstindication to the secondary sending terminal.

In combination with the fifth possible implementation manner or thesixth possible implementation manner of the first aspect, in a seventhpossible implementation manner,

before clearing the correctly received data cached in the secondarysending terminal according to the BA, the secondary sending terminal isfurther configured to receive the first indication sent by the primarysending terminal.

In combination with the seventh possible implementation manner of thefirst aspect, in an eighth possible implementation manner,

the secondary sending terminal is specifically configured to:

obtain a second indication according to the BA, wherein the secondindication is used for indicating the data correctly received by theeach receiving terminal, which is obtained by the secondary sendingterminal;

calculate a union set of the data indicated by the first indication andthe data indicated by the second indication; and

clear, according to a result of the union set calculation, datacorresponding to the result, which is cached in the secondary sendingterminal.

In a second aspect, an embodiment of the present invention provide acommunication system, including a primary sending terminal, at least onesecondary sending terminal sharing a channel with the primary sendingterminal, at least one first receiving terminal associated with theprimary sending terminal and at least one second receiving terminalassociated with the secondary sending terminal, wherein,

the primary sending terminal is configured to:

respectively send first data corresponding to each first receivingterminal to the each first receiving terminal;

respectively send a first block acknowledgement request BARcorresponding to the first data to the each first receiving terminal;

receive a first block acknowledgement BA corresponding to the first BARand sent by the each first receiving terminal respectively; and

if the first BA indicates that the first data are correctly received bythe each first receiving terminal, clear the first data cached in theprimary sending terminal, or if the first BA indicates that the firstdata are not correctly received by the each first receiving terminal,respectively retransmit first data which is not correctly received, andclear correctly received first data cached in the primary sendingterminal, wherein the first BAR and the first BA carry a preset sequenceindication, the sequence indication is used for indicating the sequenceof the secondary sending terminal for sending second BAR correspondingto second data, and the second BAR carries the sequence indication;

the secondary sending terminal is configured to:

synchronously send the second data corresponding to the each secondreceiving terminal to the each second receiving terminal with theprimary sending terminal through a shared channel;

obtain the first BA sent by the each first receiving terminal throughthe shared channel respectively, and obtain the sequence indicationaccording to the first BA;

sequentially send the second BAR to the each second receiving terminalaccording to the sequence indication respectively;

receive second BA corresponding to the second BAR and sent by the eachsecond receiving terminal respectively, wherein the second BA carriesthe sequence indication; and

if the second BA indicates that the second data are correctly receivedby the each second receiving terminal, clear the second data cached inthe secondary sending terminal, or if the second BA indicates that thesecond data are not correctly received by the each second receivingterminal, respectively retransmit the second data which is not correctlyreceived, and clear the correctly received second data cached in thesecondary sending terminal;

the first receiving terminal is configured to:

receive the first data and the first BAR sent by the primary sendingterminal; and

send the first BA corresponding to the first BAR to the primary sendingterminal; and

the second receiving terminal is configured to:

receive the second data and the second BAR sent by the secondary sendingterminal; and

send the second BA corresponding to the second BAR to the secondarysending terminal.

In a first possible implementation manner of the second aspect,

after respectively sending the first BAR corresponding to the first datato the each first receiving terminal, the primary sending terminal isfurther configured to resend, if not receiving the first BAcorresponding to the first BAR after a preset time, the first BAR toeach first receiving terminal which does not sending back the first BA.

In combination with the foregoing second aspect or the first possibleimplementation manner of the second aspect, in a second possibleimplementation manner,

after receiving the first BA sent by the each first receiving terminalrespectively, the primary sending terminal is further configured tosend, if the first BA indicates that the first data are not correctlyreceived by the each first receiving terminal, a first data indicationto the each first receiving terminal not correctly receiving the firstdata, wherein the first data indication is used for indicating the firstdata which are not correctly received by the each first receivingterminal.

In combination with the foregoing second aspect or any implementationmanner from the first possible implementation manner to the secondpossible implementation manner of the second aspect, in a third possibleimplementation manner,

after respectively sending the second BAR corresponding to the seconddata to the each second receiving terminal respectively, the secondarysending terminal is further configured to resend, if not receiving thesecond BA corresponding to the second BAR after the preset time, thesecond BAR to each second receiving terminal which does not sending backthe second BA.

In combination with the foregoing second aspect or any implementationmanner from the first possible implementation manner to the thirdpossible implementation manner of the second aspect, in a fourthpossible implementation manner,

after receiving the second BA sent by the each second receiving terminalrespectively, the secondary sending terminal is further configured tosend, if the second BA indicates that the second data are not correctlyreceived by the each second receiving terminal, a second data indicationto the each second receiving terminal not correctly receiving the seconddata, wherein the second data indication is used for indicating thesecond data which are not correctly received by the second receivingterminals.

In combination with the foregoing second aspect or any implementationmanner from the first possible implementation manner to the fourthpossible implementation manner of the second aspect, in a fifth possibleimplementation manner, there are more than two secondary sendingterminals, the sequence indication indicates that a secondary sendingterminal belonging to a same basic service set BSS as the primarysending terminal performs a sending at first, and then a secondarysending terminal not belonging to the same BSS as the primary sendingterminal performs a sending, the sequence indication includes anidentifier of the primary sending terminal and an identifier of thesecondary sending terminal, wherein the identifier of the primarysending terminal includes a media access control MAC address or anassociated identity AID of the primary sending terminal, and theidentifier of the secondary sending terminal respectively include an MACaddress or an AID of each secondary sending terminal.

In combination with the foregoing second aspect or any implementationmanner from the first possible implementation manner to the fifthpossible implementation manner of the second aspect, in a sixth possibleimplementation manner, there are more than two first receiving terminalsand more than two second receiving terminals, the sequence indicationfurther includes an identifier of the each first receiving terminal, forindicating a sequence of the each first receiving terminal for sendingthe first BA respectively, the sequence indication further includes anidentifier of the second receiving terminal, for indicating a sequenceof the each second receiving terminal for sending the second BArespectively, wherein the identifier of the each first receivingterminal respectively include an MAC address or AID of the each firstreceiving terminal, and the identifier of the each second receivingterminal respectively include an MAC address or AID of the each secondreceiving terminal.

In a third aspect, an embodiment of the present invention provide asending apparatus, applied to a wireless communication system whichobtains a channel based on a way of competition, the communicationsystem including a primary sending terminal, at least one sendingapparatus sharing a channel with the primary sending terminal and atleast one receiving terminal, wherein the sending apparatus includes:

a sending unit, configured to simultaneously send data to the eachreceiving terminal with the primary sending terminal through a sharedchannel, and simultaneously retransmit, when the each receiving terminaldo not correctly receive the data, data which is not correctly receivedwith the primary sending terminal through the shared channel;

a storage unit, configured to cache the data;

an obtaining unit, configured to obtain a block acknowledgement BA sentby the each receiving terminal through the shared channel respectively;and

a clearing unit configured to clear, if the BA indicates that the datais correctly received by the each receiving terminal respectively, thedata cached in the storage unit, or clear, if the BA indicates that thedata are not correctly received by the each receiving terminal,correctly received data cached in the storage unit.

In a first possible implementation manner of the third aspect, thesending apparatus further includes a receiving unit;

before the clearing unit clears the correctly received data cached inthe storage unit, the receiving unit is configured to receive a firstindication sent by the primary sending terminal, wherein the firstindication is used for indicating data correctly received by the eachreceiving terminal, which is obtained by the primary sending terminal.

In combination with the first possible implementation manner of thethird aspect, in a second possible implementation manner,

the obtaining unit is further configured to obtain a second indicationaccording to the BA, wherein the second indication is used forindicating the data correctly received by the each receiving terminal,which is obtained by the sending apparatus;

the clearing unit is specifically configured to calculate a union set ofthe data indicated by the first indication and the data indicated by thesecond indication, and clear, according to a result of the union setcalculation, data corresponding to the result, which cached in thestorage unit.

In a fourth aspect, the embodiments of the present invention furtherprovide a sending apparatus, applied to a wireless communication systemwhich obtains a channel based on a way of competition, the communicationsystem including a primary sending terminal, at least one sendingapparatus sharing a channel with the primary sending terminal, at leastone first receiving terminal associated with the primary sendingterminal and at least one second receiving terminal associated with thesending apparatus, wherein the sending apparatus includes:

a sending unit, configured to synchronously send second datacorresponding to each second receiving terminal to the each secondreceiving terminal with the primary sending terminal through a sharedchannel;

an obtaining unit, configured to obtain a first block acknowledgement BAsent by the each first receiving terminal through the shared channelrespectively, and obtain a preset sequence indication according to thefirst BA, wherein the first BA carries the sequence indication, thesequence indication is used for indicating a sequence of the sendingapparatus for sending a second block acknowledgement request BARcorresponding to the second data sent by the sending unit, and thesecond BAR carries the sequence indication;

the sending unit is further configured to respectively send the secondBAR to the each second receiving terminal according to the sequenceindication obtained by the obtaining unit, and respectively retransmit,when the each second receiving terminal does not correctly receive thesecond data, second data which are not correctly received;

a storage unit, configured to cache the second data;

a receiving unit, configured to receive second BA sent by the eachsecond receiving terminal respectively after the sending unitrespectively sends the second BAR, wherein the second BA carries thesequence indication;

a clearing unit configured to clear, if the second BA received by thereceiving unit indicates that the second data are correctly received bythe each second receiving terminal, the second data cached in thestorage unit, or clear if the second BA indicates that the second dataare not correctly received by the each second receiving terminal,correctly received second data cached in the storage unit.

In a first possible implementation manner of the fourth aspect,

the sending unit is further configured to resend, if the receiving unitdoes not receive second BA corresponding to the second BAR after apreset time, the second BAR to the each second receiving terminal notsending back the second BA after the sending unit respectively sends thesecond BAR corresponding to the second data to the each second receivingterminal.

In a second possible implementation manner of the fourth aspect,

the sending unit is further configured to send, if the second BAindicates that the second data are not correctly received by the eachsecond receiving terminal, a second data indication to the each secondreceiving terminal not correctly receiving the second data after thereceiving unit receives the second BA sent by the each second receivingterminal respectively, wherein the second data indication is used forindicating the second data which are not correctly received by the eachsecond receiving terminal.

In a fifth aspect, an embodiment of the present invention provides acommunication method for multiple access points, applied to a wirelesscommunication system which obtains a channel based on a way ofcompetition, the communication system including a primary sendingterminal, at least one secondary sending terminal sharing a channel withthe primary sending terminal and at least one receiving terminal,wherein the method includes:

simultaneously sending, by the secondary sending terminal, data to theeach receiving terminal with the primary sending terminal through ashared channel;

obtaining, by the secondary sending terminal, a block acknowledgement BAsent by the each receiving terminal through the shared channelrespectively; and

if the BA indicates that the data are correctly received by the eachreceiving terminal respectively, clearing, by the secondary sendingterminal, the data cached in the secondary sending terminal;

or,

if the BA indicates that the data are not correctly received by the eachreceiving terminal, simultaneously retransmitting, by the secondarysending terminal, the data which are not correctly received with theprimary sending terminal through the shared channel, and clearing, bythe secondary sending terminal, the correctly received data cached inthe secondary sending terminal.

In a first possible implementation manner of the fifth aspect, beforethe clearing, by the secondary sending terminal, the data cached in thesecondary sending terminal, the method further includes:

receiving, by the secondary sending terminal, a first indication sent bythe primary sending terminal, wherein the first indication is used forindicating the data correctly received by the each receiving terminaland obtained by the primary sending terminal.

In combination with the first possible implementation manner of thefifth aspect, in a second possible implementation manner, the clearing,by the secondary sending terminal, the data cached in the secondarysending terminal specifically includes:

obtaining, by the secondary sending terminal, a second indicationaccording to the BA, wherein the second indication is used forindicating the data correctly received by the each receiving terminal,which is obtained by the sending apparatus;

calculating, by the secondary sending terminal, a union set of the dataindicated by the first indication and the data indicated by the secondindication; and

clearing, by the secondary sending terminal according to a result of theunion set calculation, data corresponding to the result, which is cachedin the secondary sending terminal.

In a sixth aspect, an embodiment of the present invention furtherprovides a communication method for multiple access points, applied to awireless communication system which obtains a channel based on a way ofcompetition, the communication system including a primary sendingterminal, at least one secondary sending terminal sharing a channel withthe primary sending terminal, at least one first receiving terminalassociated with the primary sending terminal and at least one secondreceiving terminal associated with the secondary sending terminal,wherein the method includes:

synchronously sending, by the secondary sending terminal, second datacorresponding to each second receiving terminal to the each secondreceiving terminal with the primary sending terminal through a sharedchannel;

obtaining, by the secondary sending terminal, a first blockacknowledgement BA sent by the each first receiving terminal through theshared channel respectively, and obtaining a preset sequence indicationaccording to the first BA, wherein the first BA carries the sequenceindication, the sequence indication is used for indicating the sequenceof the secondary sending terminal for sending a second blockacknowledgement request BAR corresponding to the second data, and thesecond BAR carries the sequence indication;

respectively sending, by the secondary sending terminal, the second BARto the each second receiving terminal according to the sequenceindication;

receiving, by the secondary sending terminal, the second BAcorresponding to the second BAR and sent by the each second receivingterminal respectively, wherein the second BA carries the sequenceindication; and

if the second BA indicates that the second data are correctly receivedby the each second receiving terminal, clearing, by the secondarysending terminal, the second data cached in the secondary sendingterminal;

or,

if the second BA indicates that the second data are not correctlyreceived by the each second receiving terminal, retransmitting, by thesecondary sending terminal, second data which are not correctlyreceived, and clearing correctly received second data cached in thesecondary sending terminal.

In a first possible implementation manner of the sixth aspect, after therespectively sending, by the secondary sending terminal, the second BARto the second receiving terminals, the method further includes:

if not receiving second BA corresponding to the second BAR after apreset time, resending, by the secondary sending terminal, the secondBAR to the each second receiving terminal which does not sending backthe second BA.

In a second possible implementation manner of the sixth aspect, afterthe receiving, by the secondary sending terminal, the second BA sent bythe each second receiving terminal respectively, the method furtherincludes:

if the second BA indicates that the second data are not correctlyreceived by the each second receiving terminal, sending, by thesecondary sending terminal, a second data indication to the each secondreceiving terminal not correctly receiving the second data, wherein thesecond data indication is used for indicating the second data which arenot correctly received by the each second receiving terminal.

A communication method, apparatus and system for multiple access pointsare provided by an embodiment of the present invention, wherein afterthe primary sending terminal and the secondary sending terminalsimultaneously send the data corresponding to each receiving terminal tothe each receiving terminal through a shared channel respectively, theprimary sending terminal respectively sends the BAR corresponding to thedata to the each receiving terminal, receives a BA corresponding to theBAR which is sent by the each receiving terminal, if the BA indicatesthat the data are correctly received by the each receiving terminal,clears the data cached in the primary sending terminal, and if the BAindicates that the data are not correctly received by the each receivingterminal, retransmits data which is not correctly received and clearscorrectly received data cached in the primary sending terminal. By meansof the solution, since the primary sending terminal can learn, accordingto the BA sent back by the each receiving terminal, data receivingcondition of the each receiving terminal, retransmit the data which arenot correctly received according to the indication of the BA and clearthe correctly received data cached in the primary sending terminal whenmultiple sending terminals and multiple receiving terminals transmitdata together, error recovery for data which fails to be received by theeach receiving terminal is therefore performed, and thereby thereliability of data transmission is guaranteed and the throughput ofsystem is improved.

BRIEF DESCRIPTION OF DRAWINGS

To illustrate technical solutions in an embodiment of the presentinvention or in the prior art more clearly, a brief introduction onaccompanying drawings which are needed in description of an embodimentor the prior art is given below. Apparently, the accompanying drawingsin the description below are merely some of the embodiments of thepresent invention.

FIG. 1 is a first flowchart of a communication method for multipleaccess points provided by an embodiment of the present invention;

FIG. 2 is a first flowchart of another communication method for multipleaccess points provided by an embodiment of the present invention;

FIG. 3 is a second flowchart of a communication method for multipleaccess points provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of error recovery in cooperativetransmission provided by an embodiment of the present invention;

FIG. 5 is a third flowchart of a communication method for multipleaccess points provided by an embodiment of the present invention;

FIG. 6 is a second flowchart of another communication method formultiple access points provided by an embodiment of the presentinvention;

FIG. 7 is a structural schematic diagram of a BA provided by anembodiment of the present invention;

FIG. 8 is a structural schematic diagram of a sequence of sendingterminal and a sequence of receiving terminal provided by an embodimentof the present invention;

FIG. 9 is a structural schematic diagram of a BAR provided by anembodiment of the present invention;

FIG. 10 is a schematic diagram of error recovery in coordinatedbeamforming/interference alignment provided by an embodiment of thepresent invention;

FIG. 11 is a first structural schematic diagram of a sending apparatusprovided by an embodiment of the present invention;

FIG. 12 is a second structural schematic diagram of a sending apparatusprovided by an embodiment of the present invention;

FIG. 13 is a third structural schematic diagram of a sending apparatusprovided by an embodiment of the present invention;

FIG. 14 is a first structural schematic diagram of a beam formerprovided by an embodiment of the present invention;

FIG. 15 is a second structural schematic diagram of a beam formerprovided by an embodiment of the present invention;

FIG. 16 is a first block diagram of a communication system provided byan embodiment of the present invention; and

FIG. 17 is a second block diagram of a communication system provided byan embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

A clear and complete description of technical solutions in embodimentsof the present invention will be given below, in combination with theaccompanying drawings in the embodiments of the present invention.Apparently, the embodiments described are merely a part, but not all, ofthe embodiments of the present invention.

A variety of techniques described herein may be applied to a variety ofwireless communication systems, for example, present 2G and 3Gcommunication systems and the next generation communication system, suchas a global system for mobile communications (GSM), a code divisionmultiple access (CDMA) system, a time division multiple access (TDMA)system, a wideband code division multiple access (WCDMA) system, afrequency division multiple access (FDMA) system, an orthogonalfrequency-division multiple access (OFDMA) system, a single carrierfrequency division multiple access (SC-FDMA) system, a general packetradio service (GPRS) system, a long term evolution (LTE) system, andother similar communication systems.

Embodiment 1

An embodiment of the present invention provides a communication methodfor multiple access points. As shown in FIG. 1, it is applied to awireless communication system which obtains a channel based on a way ofcompetition. The communication system includes a primary sendingterminal, at least one secondary sending terminal sharing a channel withthe primary sending terminal and at least one receiving terminal, themethod relates to the secondary sending terminal. The method mayinclude:

S101. the secondary sending terminal simultaneously sends data to eachreceiving terminal with the primary sending terminal through a sharedchannel.

In a multiuser MIMO system, along with rapid growth of a requirement ofthroughput of the overall network, an interference problem of thenetwork has become a key factor obstructing a further improvement ofnetwork capacity. It has become a development tendency to eliminate theinterference problem of network and even to increase the throughput ofthe overall network using the network interference problem in an angleof multiple sending terminals, for example, using a method such as acooperative transmission (cooperative transmission), a coordinatedbeamforming (coordinated beamforming)/interference alignment(interference alignment), etc.

The above-mentioned cooperative transmission is that multiple sendingterminals in a multiuser MIMO system form an MIMO sending terminal withmore antennas after sharing data and channel information, and moreoverthis MIMO sending terminal with more antennas may send data to onereceiving terminal or simultaneously send data to multiple receivingterminals.

There is provided a communication method for multiple access points byan embodiment of the present invention, which is applied to the wirelesscommunication system which obtains a channel based on a way ofcompetition. The multiple sending terminals adopt a flow of errorrecovery of a cooperative transmission method during data transmission,wherein the error recovery may be defined as that a sending terminalretransmits data which are not correctly received by a receivingterminal. In data transmission, if a receiving terminal does notcorrectly receive data sent by a sending terminal, through the errorrecovery, it may be guaranteed that the receiving terminal correctlyreceives the data sent by the sending terminal.

In a wireless communication system in which multiple sending terminalssend data in a method of cooperative transmission, a primary sendingterminal (the rest sending terminals may be treated as secondary sendingterminals) needs to be preset from multiple sending terminals at first,and the primary sending terminal is responsible for obtaining areceiving condition of data sent from all sending terminals to eachreceiving terminal from each receiving terminal. Therefore, when thedata are not correctly received by the each receiving terminal, theprimary sending terminal or the primary sending terminal and acorresponding secondary sending terminal may retransmit data which arenot correctly received to each receiving terminal which does notcorrectly receive the data, so as to guarantee reliability of datatransmission.

Exemplarily, a wireless communication system provided by the embodimentof the present invention includes a primary sending terminal, at leastone secondary sending terminal sharing a channel with the primarysending terminal and at least one receiving terminal, wherein theprimary sending terminal and the at least one secondary sending terminalshare data which needs to be sent to the each receiving terminal andchannel information necessary for sending the data. During acommunication in the wireless communication system, at least onesecondary sending terminal and the primary sending terminalsimultaneously send the data corresponding to the each receivingterminal, which is to be sent, to the each receiving terminal.

If there is only one receiving terminal, the above-mentioned data aresingle-user data, and if there are two or more receiving terminals, theabove-mentioned data are multiuser data. The multiuser data containsmutually independent data for multiple receiving terminals, namely datacorresponding to the each receiving terminal. Each sending terminalcaches the multiuser data in a sharing manner and independently sendsthe multiuser data to the each receiving terminal in a spatialmultiplexing manner at the same time.

In the embodiment of the present invention, the secondary sendingterminal simultaneously sends data to the each receiving terminal withthe primary sending terminal through the shared channel, wherein thedata is data which needs to be simultaneously sent by the primarysending terminal and the secondary sending terminal to each receivingterminal and which corresponds to the each receiving terminalrespectively. Namely, the data simultaneously sent by the primarysending terminal and the secondary sending terminal to the eachreceiving terminal is mutually independent data of the each receivingterminal.

S102. the secondary sending terminal obtains a block acknowledgement(BA) sent by the each receiving terminal through the shared channelrespectively.

After the primary sending terminal and the secondary sending terminalsend the data corresponding to each receiving terminal to each receivingterminal, the primary sending terminal sends a block acknowledgementrequest (BAR) corresponding to the data to the each receiving terminal.

It should be noted that, the BAR is a request message used fordetermining a receiving conditions of the each receiving terminal on thedata sent by the primary sending terminal and the secondary sendingterminal. The BAR respectively corresponds to the data sent to the eachreceiving terminal. Namely, if there is only one receiving terminal,then there is only one BAR, and if there are multiple receivingterminals, then the BAR has single indication information for eachreceiving terminal. The specific representation manner may be that eachreceiving terminal has one BAR which is used for requesting thereceiving terminal to send a corresponding BA.

Further, each receiving terminal may generate a BA according to areceiving condition thereof on the data sent by the primary sendingterminal and the secondary sending terminal. Namely, a BA may be usedfor indicating a receiving condition of the each receiving terminal ondata, i.e., the receiving succeeds or fails, so that the primary sendingterminal and the secondary sending terminal may learn a result of datatransmission according to the BA sent back by the each receivingterminal, i.e., data transmission succeeds or fails.

Those of ordinary skill in the art may understand that, in a method ofcooperative transmission, after multiple sending terminals obtain theright of use a channel by competition, the multiple sending terminalssend the data to each receiving terminal using a same channel, namely ashared channel. Namely, the primary sending terminal and the secondarysending terminal may simultaneously send data corresponding to eachreceiving terminal to each receiving terminal. Correspondingly, theprimary sending terminal and the secondary sending terminal may alsosimultaneously receive a BA sent by each receiving terminal through theshared channel respectively. That is to say, when the each receivingterminal send the BA to the primary sending terminal, since the primarysending terminal and the secondary sending terminal share the channel,the secondary sending terminal may also obtain the BA.

S103. if the BA indicates that the data are correctly received by theeach receiving terminal respectively, the secondary sending terminalclears the data cached in the secondary sending terminal.

After a secondary sending terminal obtains a BA sent by each receivingterminal through the shared channel respectively, the secondary sendingterminal may learn a receiving condition of data of the each receivingterminal according to the BA, i.e., the receiving succeeds or fails. Ifthe BA indicates that the data are correctly received by each receivingterminal respectively, the secondary sending terminal may clear the datacached in the secondary sending terminal.

S104. if the BA indicates that the data are not correctly received bythe each receiving terminal, a secondary sending terminal simultaneouslyretransmits the data which is not correctly received with the primarysending terminal through the shared channel, and the secondary sendingterminal clears correctly received data cached in the secondary sendingterminal.

If the BA indicates that the data are not correctly received by the eachreceiving terminal, the secondary sending terminal simultaneouslyretransmits data which is not correctly received by the each receivingterminal with the primary sending terminal through the shared channel,and the secondary sending terminal clears data correctly received by theeach receiving terminal, which is cached in the secondary sendingterminal.

That the data is not correctly received by the each receiving terminal,which is mentioned above, may include: none of each receiving terminalcorrectly receives the data sent by the primary sending terminal and thesecondary sending terminal; or a part of receiving terminals correctlyreceive the data sent by the primary sending terminal and the secondarysending terminal, but a part of receiving terminals do not correctlyreceive the data sent by the primary sending terminal and the secondarysending terminal. In particular, that a certain receiving terminal doesnot correctly receive the data may include: the receiving terminal doesnot correctly receive all the data, and the receiving terminal does notcorrectly receive a part of the data.

In particular, the secondary sending terminal and the primary sendingterminal retransmit the data which is not correctly received by the eachreceiving terminal, namely performing error recovery of the data toguarantee reliability of data transmission.

It should be noted that, since the multiple sending terminals and themultiple receiving terminals share a channel, for a BA from the eachreceiving terminal, the secondary sending terminal and the primarysending terminal may simultaneously receive the BA.

There is provided a communication method for multiple access points bythe embodiment of the present invention. Since error recovery can besupported during the multiple sending terminals and the multiplereceiving terminals transmit the data simultaneously, thereby thereliability of data transmission is guaranteed and the throughput of thesystem is improved.

There is provided a communication method for multiple access points bythe embodiment of the present invention. The secondary sending terminaland the primary sending terminal simultaneously send the datacorresponding to each receiving terminal to each receiving terminalthrough the shared channel respectively, and the secondary sendingterminal obtains the BA sent by the each receiving terminal through theshared channel respectively. If the BA indicates that the data arecorrectly received by the each receiving terminal, the data cached inthe primary sending terminal is cleared, and if the BA indicates thatthe data are not correctly received by the receiving terminals, the datawhich are not correctly received is retransmitted and the correctlyreceived data cached in the primary sending terminal is cleared. Bymeans of the solution, since the primary sending terminal can learn,according to the BA sent back by the each receiving terminal, datareceiving condition of the each receiving terminal, retransmit the datawhich are not correctly received according to the indication of the BAand clear the correctly received data cached in the primary sendingterminal when multiple sending terminals and multiple receivingterminals transmit data together, error recovery for data which fails tobe received by the each receiving terminal is therefore performed, andthereby the reliability of data transmission is guaranteed and thethroughput of system is improved.

An embodiment of the present invention provides another communicationmethod for multiple access points. As shown in FIG. 2, the communicationmethod is applied to a wireless communication system which obtains achannel based on a way of competition. The communication system includesa primary sending terminal, at least one secondary sending terminalsharing a channel with the primary sending terminal, at least one firstreceiving terminal associated with the primary sending terminal and atleast one second receiving terminal associated with the secondarysending terminal. The method relates to a secondary sending terminal,and the method may include:

S201. the secondary sending terminal synchronously sends second datacorresponding to each second receiving terminal to each second receivingterminal with the primary sending terminal through a shared channel.

In a multiuser MIMO system, along with rapid growth of a requirement ofthroughput of the overall network, an interference problem of thenetwork has become a key factor obstructing a further improvement ofnetwork capacity. It has become a development tendency to eliminate theinterference problem of network and even to increase the throughput ofthe overall network using the network interference problem in an angleof multiple sending terminals, for example, using a method such as acooperative transmission, a coordinated beamforming/interferencealignment, etc.

The above-mentioned coordinated beamforming is that after multiplesending terminals in the multiuser MIMO system share a part of or all ofchannel information, a reasonable transmission solution is calculatedaccording to the respective transmission features of the multiplesending terminals to enable the multiple sending terminals tosimultaneously send data to multiple receiving terminals, and mutualnon-interference or mutual interference may be ignored to a certaindegree. The interference alignment is that after multiple sendingterminals simultaneously send data, signals arriving at receivingterminals lie in an orthogonal dimension which makes the receivingterminals separate useful signals effectively.

There is provided another communication method for multiple accesspoints by the embodiment of the present invention, which is applied to awireless communication system obtaining a channel based on a way ofcompetition. The multiple sending terminals adopt a flow of errorrecovery of a method of coordinated beamforming/interference alignmentduring data transmission.

In a wireless communication system in which the multiple sendingterminals send data using a method of coordinatedbeamforming/interference alignment, a primary sending terminal needs tobe preset from the multiple sending terminals at first. Then, startingfrom the primary sending terminal, the multiple sending terminalssequentially obtain a receiving condition of each receiving terminal onthe data sent by the same, so that when the each receiving terminal doesnot correctly receive the data, a corresponding sending terminal mayretransmit data which are not correctly received to the correspondingreceiving terminal, so as to guarantee reliability of data transmission.

In the method of coordinated beamforming/interference alignment which isadopted in the embodiment of the present invention, after the secondarysending terminal and the primary sending terminal share a part of or allof channel information, the primary sending terminal respectively sendsfirst data corresponding to each first receiving terminal to each firstreceiving terminal associated with the primary sending terminal.Meanwhile, the secondary sending terminal respectively sends second datacorresponding to each second receiving terminal to each second receivingterminal associated with the secondary sending terminal. Namely, thesecondary sending terminal synchronously sends the second datacorresponding to each second receiving terminal to each second receivingterminal with the primary sending terminal through the shared channel.

It should be noted that, “association” is a result of an associationflow in the prior art. Specifically, a receiving terminal sends anassociation request to a sending terminal, and if the sending terminalaccepts the association with the receiving terminal, namely, accepts toprovide a service for the receiving terminal, it indicates that thereceiving terminal is associated with the sending terminal.

Further, there are many reasons for determining whether the receivingterminal can be successfully associated with the sending terminal. Forexample, if receiving terminals which can be served by the sendingterminal have reached an upper limit, then the association request sentby the receiving terminal will not be accepted by the sending terminal,namely the receiving terminal is not associated with the sendingterminal.

If there is only one receiving terminal, the above-mentioned data aresingle-user data, and if there are two or more receiving terminals, theabove-mentioned data are multiuser data. The multiuser data containsmutually independent data for multiple receiving terminals. Each sendingterminal caches the multiuser data in a sharing manner and independentlysends the multiuser data to the each receiving terminal in a spatialmultiplexing manner at the same time.

S202. the secondary sending terminal obtains a first BA sent by eachfirst receiving terminal through the shared channel respectively, andobtains a preset sequence indication according to the first BA, whereinthe first BA carries the sequence indication, the sequence indication isused for indicating a sequence of the secondary sending terminal forsending second BAR corresponding to the second data, and the second BARcarries the sequence indication.

After the secondary sending terminal sends the second data to eachsecond receiving terminal, the secondary sending terminal firstlyobtains the first BA sent by each first receiving terminal through theshared channel respectively, wherein the first BA carries the presetsequence indication. The sequence indication may be used for indicatingthe sequence of the secondary sending terminal for sending the secondBAR corresponding to the second data. Namely each secondary sendingterminal in the secondary sending terminals may sequentially send thesecond BAR to each second receiving terminal according to the sequenceindication. The second BAR also carries the sequence indication.

It should be noted that, each receiving terminal may generate acorresponding BA according to a receiving condition thereof on data sentby the primary sending terminal and the secondary sending terminal.Namely, the BA may be used for indicating that the receiving of data ofeach receiving terminal, which is sent by the primary sending terminaland the secondary sending terminal, succeeds or fails.

Those of ordinary skill in the art may understand that, in a method ofcoordinated beamforming/interference alignment, after multiple sendingterminals obtain the right of use of a channel by competition, themultiple sending terminals use a same channel to send the data toreceiving terminals. Namely, the secondary sending terminal and theprimary sending terminal may synchronously send first data and seconddata of each receiving terminal associated with them to each receivingterminal associated with them respectively. Correspondingly, since thesecondary sending terminal and the primary sending terminal share achannel, when a first receiving terminal send a first BA to a primarysending terminal, a secondary sending terminal can also obtain the firstBA.

S203. the secondary sending terminal respectively sends the second BARto each second receiving terminal according to the sequence indication.

After the secondary sending terminal obtains the first BA, the secondarysending terminal may respectively send a second BAR to each secondreceiving terminal according to the sequence indication carried in thefirst BA. Namely, the secondary sending terminal sequentially sends thesecond BAR corresponding to the second data of each second receivingterminal to each second receiving terminal according to the sequenceindication.

S204. the secondary sending terminal receives the second BAcorresponding to the second BAR, which is sent by each second receivingterminal respectively, wherein the second BA carries the sequenceindication.

After the secondary sending terminal sends the second BAR, the secondarysending terminal may receive the second BA corresponding to the secondBAR, which is sent by each second receiving terminal respectively,wherein the second BA carries the sequence indication. This is becauseother secondary sending terminals may continue to sequentially send theBAR according to the sequence indication carried in the second BAR.

It should be noted that, in the another communication method formultiple access points provided by the embodiment of the presentinvention, at first, the primary sending terminal respectively sends thefirst BAR corresponding to the first data to each first receivingterminal to request a receiving condition of each first receivingterminal on the first data. After each first receiving terminalrespectively send back the first BA, the secondary sending terminals maysequentially send the second BAR corresponding to the second data toeach second receiving terminal associated with the same according to thesequence indication in the first BA to request a receiving condition ofeach second receiving terminal on the second data until all the sendingterminals (including the primary sending terminal and the secondarysending terminals) send requests to each receiving terminalparticipating in present data transmission for at least one time.

S205. if the second BA indicates that the second data is correctlyreceived by each second receiving terminal respectively, the secondarysending terminal clears the second data cached in the secondary sendingterminal.

After the secondary sending terminal receives the second BA sent by eachsecond receiving terminal respectively, the secondary sending terminalmay learn a receiving condition of each second receiving terminal on thesecond data, namely the receiving of the second data succeeds or failsfor each second receiving terminal. If the second BA indicates that thesecond data are correctly received by each second receiving terminalrespectively, the secondary sending terminal may clear the second datacached in the secondary sending terminal.

S206. if the second BA indicates that the second data is not correctlyreceived by each second receiving terminal, the secondary sendingterminal retransmits second data which is not correctly received, andclears correctly received second data cached in the secondary sendingterminal.

If the second BA indicates that the second data are not correctlyreceived by each second receiving terminal, the secondary sendingterminal may retransmit second data which are not correctly received andclear correctly received second data cached in the secondary sendingterminal, so as to guarantee reliability of transmission of the seconddata.

That the second data is not correctly received by each second receivingterminal, which is mentioned above, may include: none of each secondreceiving terminal correctly receive the second data sent by thesecondary sending terminal; or a part of the second receiving terminalscorrectly receive the data sent by the secondary sending terminal, but apart of the second receiving terminals do not correctly receive thesecond data sent by the secondary sending terminal.

In particular, the secondary sending terminal retransmits the seconddata which is not correctly received by each second receiving terminal.Namely error recovery of the second data is performed to guaranteereliability of transmission of the second data.

It should be noted that, since the multiple sending terminals and themultiple receiving terminals share the channel, for a BA from eachreceiving terminal, the secondary sending terminal and the primarysending terminal may simultaneously receive the BA.

It should be noted that, when each second receiving terminal sends thesecond BA through the shared channel, the primary sending terminal mayalso receive the second BA. However, since the second BA and thesequence indication carried in the second BA are merely used forindicating other secondary sending terminals not sending the BAR toexecute corresponding steps, a process of the primary sending terminalfor receiving the second BA will not be described in detail in theembodiment of the present invention.

Since the error recovery between multiple sending terminals and multiplereceiving terminals during simultaneous data transmission can besupported, the another communication method for multiple access pointsprovided by the embodiment of the present invention thereby guaranteesthe reliability of data transmission and the throughput of the system isimproved.

There is provided another communication method for multiple accesspoints provided by the embodiment of the present invention, after thesecondary sending terminal and the primary sending terminalsynchronously send the second data corresponding to each secondreceiving terminal to each second receiving terminal, a secondarysending terminal obtains the first BA sent by each first receivingterminal through the shared channel respectively. The secondary sendingterminal sends the second BAR corresponding to the second data to eachsecond receiving terminal according to the sequence indication carriedin the first BA, and receives the second BA corresponding to the secondBAR, which is sent by each second receiving terminal respectively. Ifthe second BA indicates that the second data is correctly received byeach second receiving terminal, the second data cached in the secondarysending terminal is cleared, and if the second BA indicates that thesecond data is not correctly received by the second receiving terminals,the second data which is not correctly received is retransmitted and thecorrectly received second data cached in the secondary sending terminalis cleared. By means of the solution, since the primary sending terminalcan learn, according to the BA sent back by the each receiving terminal,data receiving condition of the each receiving terminal, retransmit thedata which are not correctly received according to the indication of theBA and clear the correctly received data cached in the primary sendingterminal when multiple sending terminals and multiple receivingterminals transmit data together, error recovery for data which fails tobe received by the each receiving terminal is therefore performed, andthereby the reliability of data transmission is guaranteed and thethroughput of system is improved.

Embodiment 2

An embodiment of the present invention provides a communication methodfor multiple access points. As shown in FIG. 3, it is applied to awireless communication system which obtains a channel based on a way ofcompetition. The communication system includes a primary sendingterminal, at least one secondary sending terminal sharing a channel withthe primary sending terminal and at least one receiving terminal. Themethod may include:

S301. the primary sending terminal and the secondary sending terminalsimultaneously send data corresponding to each receiving terminal toeach receiving terminal.

In a multiuser MIMO system, along with rapid growth of a requirement ofthroughput of the overall network, an interference problem of thenetwork has become a key factor obstructing a further improvement ofnetwork capacity. It has become a development tendency to eliminate theinterference problem of network and even to increase the throughput ofthe overall network using the network interference problem in an angleof multiple sending terminals, for example, using a method such as acooperative transmission, a coordinated beamforming/interferencealignment, etc.

The above-mentioned cooperative transmission is that multiple sendingterminals in a multiuser MIMO system form an MIMO sending terminal withmore antennas after sharing data and channel information, and moreoverthis MIMO sending terminal with more antennas may send data to onereceiving terminal or simultaneously send data to multiple receivingterminals.

There is provided a communication method for multiple access points byan embodiment of the present invention, which is applied to the wirelesscommunication system which obtains a channel based on a way ofcompetition. The multiple sending terminals adopt a flow of errorrecovery of a cooperative transmission method during data transmission,wherein the error recovery may be defined as that a sending terminalretransmits data which are not correctly received by a receivingterminal. In data transmission, if a receiving terminal does notcorrectly receive data sent by a sending terminal, through the errorrecovery, it may be guaranteed that the receiving terminal correctlyreceives the data sent by the sending terminal.

In a wireless communication system in which multiple sending terminalssend data in a method of cooperative transmission, a primary sendingterminal (the rest sending terminals may be treated as secondary sendingterminals) needs to be preset from multiple sending terminals at first,and the primary sending terminal is responsible for obtaining areceiving condition of data sent from all sending terminals to eachreceiving terminal from each receiving terminal. Therefore, when thedata are not correctly received by the each receiving terminal, theprimary sending terminal or the primary sending terminal and acorresponding secondary sending terminal may retransmit data which arenot correctly received to each receiving terminal which does notcorrectly receive the data, so as to guarantee reliability of datatransmission.

Exemplarily, a wireless communication system provided by the embodimentof the present invention includes a primary sending terminal, at leastone secondary sending terminal sharing a channel with the primarysending terminal and at least one receiving terminal, wherein theprimary sending terminal and the at least one secondary sending terminalshare data which needs to be sent to the each receiving terminal andchannel information necessary for sending the data. During acommunication in the wireless communication system, at least onesecondary sending terminal and the primary sending terminalsimultaneously send the data corresponding to the each receivingterminal, which is to be sent, to the each receiving terminal.

If there is only one receiving terminal, the above-mentioned data aresingle-user data, and if there are two or more receiving terminals, theabove-mentioned data are multiuser data. The multiuser data containsmutually independent data for multiple receiving terminals, namely datacorresponding to the each receiving terminal. Each sending terminalcaches the multiuser data in a sharing manner and independently sendsthe multiuser data to the each receiving terminal in a spatialmultiplexing manner at the same time.

In the embodiment of the present invention, the secondary sendingterminal simultaneously sends data to the each receiving terminal withthe primary sending terminal through the shared channel, wherein thedata is data which needs to be simultaneously sent by the primarysending terminal and the secondary sending terminal to each receivingterminal and which corresponds to the each receiving terminalrespectively. Namely, the data simultaneously sent by the primarysending terminal and the secondary sending terminal to the eachreceiving terminal is mutually independent data of the each receivingterminal.

S302. each receiving terminal generates corresponding first BA accordingto a receiving condition on the data.

After each receiving terminal receive the data sent by the primarysending terminal and the secondary sending terminal, each receivingterminal may generate corresponding BA according to the receivingcondition on the data.

It should be noted that, a BA may be used for indicating a receivingcondition of the each receiving terminal on data, i.e., the receivingsucceeds or fails, so that the primary sending terminal and thesecondary sending terminal may learn that the receiving of eachreceiving terminal for the data which is sent by the primary sendingterminal and the secondary sending terminal succeeds or fails.

S303. the primary sending terminal sends the BAR corresponding to thedata to each receiving terminal.

After the primary sending terminal and the secondary sending terminalsimultaneously send the data corresponding to each receiving terminal toeach receiving terminals, the primary sending terminal may send the BARcorresponding to the data to each receiving terminal, wherein the BARmay be used for requesting a receiving condition of each receivingterminal on the data sent by the primary sending terminal and thesecondary sending terminal.

Optionally, the primary sending terminal may respectively send the BARto each receiving terminal according to a preset sequence, wherein thepreset sequence may be that a BAR is sent to each receiving terminalbelonging to the same basic service set (BSS) as the primary sendingterminal at first and then a BAR is sent to each receiving terminal notbelonging to the same BSS as the primary sending terminal.

Optionally, the sequence of the primary sending terminal for sending theBAR may be determined by the primary sending terminal. A feasible methodis that the primary sending terminal presets the sequence of sending aBAR before sending the data and sends the BAR to each receiving terminalof the data according to the preset sequence after the data is sent.Namely, the primary sending terminal may sequentially send the BAR toeach receiving terminal according to the above-mentioned presetsequence. The primary sending terminal may also determine a sequence ofsending the next BAR after sending the former BAR, which is not limitedin the present invention.

It should be noted that, the BAR may be used for requesting a receivingcondition of each receiving terminal on the data sent by the primarysending terminal and the secondary sending terminal, namely a receivingof a receiving terminal succeeds or fails.

Specifically, the primary sending terminal may send a BAR to eachreceiving terminal after the primary sending terminal and the secondarysending terminal simultaneously send the data to each receivingterminal. Namely the primary sending terminal sends the BAR in anexplicit manner. The BAR may also be carried when the primary sendingterminal and the secondary sending terminal simultaneously send the datato each receiving terminal. Namely the primary sending terminal sendsthe BAR in an implicit manner, which is not limited in the presentinvention.

Further, the preset sequence provided by the embodiment of the presentinvention may be that a receiving terminal in the BSS is preferentialand a receiving terminal out of the BSS takes a second place. The presetsequence may also be any other sequence satisfying a communicationrequirement, which is not limited in the present invention, for example,a receiving terminal out of the BSS is preferential and a receivingterminal in the BSS takes the second place. Specifically, in a case ofmultiple first receiving terminals, the sequence of the primary sendingterminal for sending the first BAR to the multiple first receivingterminals may be that the primary sending terminal firstly sends thefirst BAR to first receiving terminals belonging to the same BSS as theprimary sending terminal and then sends the first BAR to first receivingterminals not belonging to the same BSS as the primary sending terminal;the sequence may also be that the primary sending terminal firstly sendsthe first BAR to first receiving terminals not belonging to the same BSSas the primary sending terminal and then sends the first BAR to firstreceiving terminals belonging to the same BSS as the primary sendingterminal.

It may be understood that, in the communication method for multipleaccess points provided by the embodiment of the present invention, theprimary sending terminal may sequentially send the first BAR to allreceiving terminals (including receiving terminals associated with theprimary sending terminal and receiving terminals associated with thesecondary sending terminal). However, in the prior art, the primarysending terminal may only send the first BAR to a receiving terminalassociated with the primary sending terminal.

In the present invention, the execution sequence of S302 and S303 is notlimited. Namely, in the present invention, S302 may be executed beforeS303; S303 may be executed before S302; or S302 and S303 may also besimultaneously executed.

S304. each receiving terminal respectively sends BA corresponding to theBAR to the primary sending terminal.

After each receiving terminal respectively generate the BA, eachreceiving terminal respectively send, if the BAR requesting the BA fromthe primary sending terminal is received, the BA corresponding to theBAR to the primary sending terminal.

It should be noted that, after the BAR is sent, the primary sendingterminal may start to receive the BA corresponding to the BAR after afirst preset time, wherein the first preset time may be a shortinter-frame space (SIFS). The SIFS provided by the embodiment of thepresent invention may be defined as a receiving time of the receivingterminal+a receiving/sending conversion time+a sending time of a symbol.

Further, the first preset time provided by the embodiment of the presentinvention starts to be calculated after a sending terminal sends a BAR.Namely, the first preset time in the embodiment of the present inventionstarts to be calculated after the primary sending terminal sends theBAR.

Those of ordinary skill in the art may understand that, in the method ofcooperative transmission, after the multiple sending terminals obtainthe right of use a channel by competition, since the primary sendingterminal and the secondary sending terminal share the channel, themultiple sending terminals use the same channel to respectively senddata corresponding to each receiving terminal to each receivingterminal. Namely, the primary sending terminal and the secondary sendingterminal may simultaneously send the data of each receiving terminal toeach receiving terminal. Correspondingly, the primary sending terminaland the secondary sending terminal may also simultaneously receive theBA sent by each receiving terminal respectively.

As shown in FIG. 4, it is a schematic diagram of error recovery incooperative transmission of multiple sending terminals. The multiplesending terminals share data needing to be sent to each receivingterminal and simultaneously send the data to the corresponding eachreceiving terminal. Then the primary sending terminal sequentially sendsa BAR corresponding to the data of each receiving terminal to thecorresponding each receiving terminal, so that each receiving terminalsend back the BA, which indicates a receiving conditions thereof on thedata and corresponds to the BAR, to the primary sending terminal.

S305. if the BA indicates that the data are correctly received by eachreceiving terminal, the primary sending terminal and the secondarysending terminal respectively clear the data cached in the primarysending terminal and the secondary sending terminal.

After the primary sending terminal and the secondary sending terminalobtain the BA sent by each receiving terminal, the primary sendingterminal and the secondary sending terminal may learn a receivingcondition of each receiving terminal on the data according to the BA,namely the receiving of the data succeeds or fails. If the BA indicatesthat the data are correctly received by each receiving terminal, theprimary sending terminal and the secondary sending terminal respectivelyclear the data cached therein.

S306. if the BA indicates that the data is not correctly received byeach receiving terminal, the primary sending terminal and the secondarysending terminal simultaneously retransmit data which is not correctlyreceived through the shared channel and clear correctly received datacached therein respectively.

If the BA indicates that the data are not correctly received by eachreceiving terminal, the primary sending terminal and the secondarysending terminal may simultaneously retransmit the data which are notcorrectly received through the shared channel. Alternatively, theprimary sending terminal may singly retransmit the data which are notcorrectly received, wherein the secondary sending terminal onlyretransmits corresponding data only when the primary sending terminalneeds the secondary sending terminal to participate in retransmission.

Optionally, after the primary sending terminal receives the BArespectively sent by the receiving terminals, if the BA indicates thatthe data are not correctly received by the receiving terminals, theprimary sending terminal may send a data indication to the receivingterminals not correctly receiving the data, wherein the data indicationmay be used for indicating the data which are not correctly received bythe receiving terminals.

That the data is not correctly received by the each receiving terminal,which is mentioned above, may include: none of each receiving terminalcorrectly receives the data sent by the primary sending terminal and thesecondary sending terminal; or a part of receiving terminals correctlyreceive the data sent by the primary sending terminal and the secondarysending terminal, but a part of receiving terminals do not correctlyreceive the data sent by the primary sending terminal and the secondarysending terminal. In particular, that a certain receiving terminal doesnot correctly receive the data may include: the receiving terminal doesnot correctly receive all the data it corresponds to, or the receivingterminal does not correctly receive a part of data it corresponds to.

When each receiving terminal does not correctly receive the data or onlycorrectly receive a part of the data, the primary sending terminal mayrespectively send the data which is not correctly received by eachreceiving terminal to each receiving terminal again. Alternatively, theprimary sending terminal and the secondary sending terminal send datawhich is not correctly received by each receiving terminal to eachreceiving terminal again through the shared channel simultaneously, soas to perform error recovery for the data which fails to be received byeach receiving terminal, namely to initiate retransmission. In a casethat the secondary sending terminal retransmits data which is notcorrectly received, the secondary sending terminal retransmits thecorresponding data only when the primary sending terminal requires thesecondary sending terminal to participate in retransmission.

It should be noted that, since the primary sending terminal and thesecondary sending terminal adopt a manner of cooperative transmission,after the primary sending terminal and the secondary sending terminalobtain the BA sent by each receiving terminal respectively, the primarysending terminal and the secondary sending terminal perform certaininformation interaction. As shown in FIG. 5, it may specifically includethe following steps.

(1) The primary sending terminal obtains a first indication indicatingdata correctly received by each receiving terminal according to the BA;the secondary sending terminal obtains a second indication indicatingdata correctly received by each receiving terminal according to the BA.

(2) The primary sending terminal clears, according to the firstindication, the data corresponding to the first indication, which iscached in the primary sending terminal, and meanwhile the primarysending terminal sends the first indication to the secondary sendingterminal.

(3) After receiving the first indication, the secondary sending terminalcalculates a union set of the data indicated by the first indication andthe data indicated by the second indication, and clears, according to aresult of union set calculation, data corresponding to the result, whichis cached in the secondary sending terminal.

Optionally, (4) the secondary sending terminal compares the dataindicated by the first indication with the data indicated by the secondindication. If the data indicated by the second indication is largerthan the data indicated by the first indication, the secondary sendingterminal sends a third indication which indicates the extra data to theprimary sending terminal. If the data indicated by the second indicationis smaller than the data indicated by the first indication, thesecondary sending terminal waits to receive the next BA.

(5) If the primary sending terminal receives the third indication fromthe secondary sending terminal, the primary sending terminal clears,according to the third indication, data corresponding to the thirdindication, which is cached in the primary sending terminal and waits toreceive the next BA.

Optionally, the secondary sending terminal may only clear, according tothe first indication sent by the primary sending terminal, the datacorresponding to the first indication, which is cached in the secondarysending terminal without obtaining the first BA sent by each receivingterminal.

In the communication method for multiple access points provided by theembodiment of the present invention, S302 to S306 may be executedrepeatedly until each receiving terminal contained in the presetsequence receive at least one BAR or a time network allocation vector(NAV) previously reserved in the system is terminated.

Further, after the primary sending terminal and the secondary sendingterminal send data, no signal can be sent within a time period betweenthe primary sending terminal sends the BAR to each receiving terminaland receives the BA sent by each receiving terminal, and the competitionof the right of use the channel can be started again until the reservedtime NAV is terminated.

S307. after the BAR corresponding to the data is sent to each receivingterminal, the primary sending terminal resends, if the BA correspondingto the BAR is not received after a preset time, the BAR to eachreceiving terminal which does not sending back the BA.

After the primary sending terminal sends the BAR, the primary sendingterminal resends, if the primary sending terminal does not receive theBA sent by each receiving terminal after the preset time, the BAR toeach receiving terminal, which does not sending back the BA.

It should be noted that, the above-mentioned preset time may be a pointcoordination function inter-frame space (PIFS), and PIFS is larger thanSIFS, wherein the PIFS provided by the embodiment of the presentinvention may be defined as SIFS+slot time (slot time).

Optionally, the above-mentioned data indication may be sent by beingcarried in a BAR. It may also be sent by being carried in othermessages, which is not limited in the present invention.

Further, the above-mentioned preset time is similar to the first presettime and starts to be calculated after the sending terminal sends theBAR. The preset time in the above-mentioned S307 starts to be calculatedafter the primary sending terminal sends the BAR.

There is provided a communication method for multiple access points bythe embodiment of the present invention. Since error recovery can besupported during the multiple sending terminals and the multiplereceiving terminals transmit the data simultaneously, thereby thereliability of data transmission is guaranteed and the throughput of thesystem is improved

There is provided a communication method for multiple access points bythe embodiment of the present invention. After the primary sendingterminal and the secondary sending terminal simultaneously send the datacorresponding to each receiving terminal to each receiving terminalthrough the shared channel respectively, the primary sending terminalrespectively sends the BAR corresponding to the data to each receivingterminal. The primary sending terminal and the secondary sendingterminal obtain the BA corresponding to the BAR, which is sent by eachreceiving terminal through the shared channel. If the BA indicates thatthe data are correctly received by each receiving terminal, the primarysending terminal and the secondary sending terminal respectively clearthe data cached therein, and if the BA indicates that the data are notcorrectly received by each receiving terminal, the primary sendingterminal and the secondary sending terminal retransmit the data whichare not correctly received and respectively clear the correctly receiveddata cached therein. By means of the solution, when the multiple sendingterminals and the multiple receiving terminals transmit the datatogether, the multiple sending terminals may learn, according to the BAsent back by each receiving terminal, the receiving condition of eachreceiving terminal on the data, retransmit the data which is notcorrectly received according to the indication of the BA, clear thecorrectly received data cached therein respectively, and thereforeperform error recovery for the data which fails to be received by eachreceiving terminal, namely initiate retransmission, thereby guaranteeingreliability of data transmission and improving throughput of system.

There is provided another communication method for multiple accesspoints by an embodiment of the present invention. As shown in FIG. 6, itis applied to a wireless communication system which obtains a channelbased on a way of competition. The communication system includes aprimary sending terminal, at least one secondary sending terminalsharing a channel with the primary sending terminal, at least one firstreceiving terminal associated with the primary sending terminal and atleast one second receiving terminal associated with the secondarysending terminal. The method may include:

S401. the primary sending terminal respectively sends first datacorresponding to each first receiving terminal to each first receivingterminal, and meanwhile the secondary sending terminal respectivelysends second data corresponding to each second receiving terminal toeach second receiving terminal.

In a multiuser MIMO system, along with rapid growth of a requirement ofthroughput of the overall network, an interference problem of thenetwork has become a key factor obstructing a further improvement ofnetwork capacity. It has become a development tendency to eliminate theinterference problem of network and even to increase the throughput ofthe overall network using the network interference problem in an angleof multiple sending terminals, for example, using a method such as acooperative transmission, a coordinated beamforming/interferencealignment, etc.

The above-mentioned coordinated beamforming is that after multiplesending terminals in the multiuser MIMO system share a part of or all ofchannel information, a reasonable transmission solution is calculatedaccording to the respective transmission features of the multiplesending terminals to enable the multiple sending terminals tosimultaneously send data to multiple receiving terminals, and mutualnon-interference or mutual interference may be ignored to a certaindegree. The interference alignment is that after multiple sendingterminals simultaneously send data, signals arriving at receivingterminals lie in an orthogonal dimension which makes the receivingterminals separate useful signals effectively.

There is provided another communication method for multiple accesspoints by the embodiment of the present invention, which is applied to awireless communication system obtaining a channel based on a way ofcompetition. The multiple sending terminals adopt a flow of errorrecovery of a method of coordinated beamforming/interference alignmentduring data transmission.

In a wireless communication system in which the multiple sendingterminals send data using a method of coordinatedbeamforming/interference alignment, a primary sending terminal needs tobe preset from the multiple sending terminals at first. Then, startingfrom the primary sending terminal, the multiple sending terminalssequentially obtain a receiving condition of each receiving terminal onthe data sent by the same, so that when the each receiving terminal doesnot correctly receive the data, a corresponding sending terminal mayretransmit data which are not correctly received to the correspondingreceiving terminal, so as to guarantee reliability of data transmission.

In the method of coordinated beamforming/interference alignment which isadopted in the embodiment of the present invention, after a firstsecondary sending terminal and the primary sending terminal share a partof or all of channel information, the primary sending terminalrespectively sends first data corresponding to each first receivingterminal to each first receiving terminal associated with the primarysending terminal. Meanwhile, the secondary sending terminal respectivelysends second data corresponding to each second receiving terminal toeach second receiving terminal associated with the secondary sendingterminal.

It should be noted that, “association” is a result of an associationflow in the prior art. Specifically, a receiving terminal sends anassociation request to a sending terminal, and if the sending terminalaccepts the association with the receiving terminal, namely, accepts toprovide a service for the receiving terminal, it indicates that thereceiving terminal is associated with the sending terminal.

Further, there are many reasons for determining whether the receivingterminal can be successfully associated with the sending terminal. Forexample, if receiving terminals which can be served by the sendingterminal have reached an upper limit, then the association request sentby the receiving terminal will not be accepted by the sending terminal,namely the receiving terminal is not associated with the sendingterminal.

If there is only one receiving terminal, the above-mentioned data aresingle-user data, and if there are two or more receiving terminals, theabove-mentioned data are multiuser data. The multiuser data containsmutually independent data for multiple receiving terminals. Each sendingterminal caches the multiuser data in a sharing manner and independentlysends the multiuser data to the each receiving terminal in a spatialmultiplexing manner at the same time.

It may be understood that, the first data is data respectivelycorresponding to each first receiving terminal, and the second data isdata respectively corresponding to the second receiving terminal.

S402. each first receiving terminal respectively generates correspondingfirst BA corresponding to a receiving condition thereof on the firstdata.

After each first receiving terminal receives the first data, each firstreceiving terminal respectively generate the first BA corresponding tothe receiving condition thereof on the first data.

It should be noted that, the first BA may be used for indicating thereceiving condition of each first receiving terminal on the first data,namely, the receiving succeeds or fails, so that the primary sendingterminal may learn, according to the first BA, the receiving conditionof each first receiving terminals on the first data sent from theprimary sending terminal to each first receiving terminal.

S403. the primary sending terminal respectively sends first BARcorresponding to the first data to each first receiving terminal,wherein the first BAR carries a preset sequence indication.

After the primary sending terminal respectively sends the first datacorresponding to each first receiving terminal to each first receivingterminal, and meanwhile the secondary sending terminal respectivelysends the second data corresponding to each second receiving terminal toeach second receiving terminal, the primary sending terminalrespectively sends the first BAR corresponding to the first data to eachfirst receiving terminal at first, the first BAR carries a presetsequence indication, wherein the sequence indication is used forindicating a sequence of the secondary sending terminal for sendingsecond BAR corresponding to the second data. Namely each secondarysending terminal sequentially sends the second BAR to each secondreceiving terminal associated with the same according to the sequenceindication. The second BAR also carries the sequence indication, forindicating the secondary sending terminals not sending the second BAR tosequentially send the second BAR according to the sequence indication.

It may be understood that, the primary sending terminal may respectivelysend the first BAR to each first receiving terminal after respectivelysending the first data to each first receiving terminal, namely sendingthe first BAR in an explicit manner. The primary sending terminal mayalso carry the first BAR when the first data is respectively sent toeach first receiving terminal, namely sending the first BAR in animplicit manner, which is not limited in the present invention.

It should be noted that, the first BAR is a request message used foracknowledging the receiving condition of each first receiving terminalon the first data sent by the primary sending terminal; and the secondBAR is a request message used for acknowledging the receiving conditionof each second receiving terminal on the second data sent by thesecondary sending terminal.

Further, if there are more than two secondary sending terminals, thepreset sequence indication provided in the embodiment of the presentinvention may be that the secondary sending terminals belonging to asame BSS as the primary sending terminal perform sending at first andthe secondary sending terminals not belonging to the same BSS as theprimary sending terminal perform sending subsequently. Specifically, incase of multiple secondary sending terminals, the sequence of thesecondary sending terminals for sending the second BAR may be thatsecondary sending terminals belonging to the same BSS as the primarysending terminal send second BAR to second receiving terminalsassociated with the same at first and secondary sending terminals notbelonging to the same BSS as the primary sending terminal send thesecond BAR to second receiving terminals associated with the samesubsequently.

Exemplarily, in a schematic diagram of the first BA or the second BA asshown in FIG. 7, the sequence indication may include an identifier ofthe primary sending terminal and identifiers of secondary sendingterminals, which is used for indicating the sequence of the secondarysending terminals for sending the BAR, wherein the identifier of theprimary sending terminal includes a media access control (MAC) addressof the primary sending terminal or an associated identity (AID) of theprimary sending terminal, and the identifiers of the secondary sendingterminals may include the MAC addresses of the secondary sendingterminals or the AIDs of the secondary sending terminals.

Further, the first BA or the second BA may further include BA control,BA information and forward error correction operator and the like. Theposition of the sequence of the sending terminals in the sequenceindication in the first BA or the second BA may be exchanged with theposition of the BA information in the first BA or the second BA. Inaddition, in order to effectively express the existence of a sequenceindication in the first BA or the second BA, an expression bit needs tobe added in the MAC address or the BA control for expressing theexistence of the sequence indication in the first BA or the second BA.

If there are more than two first receiving terminals, the sequenceindication may further include identifiers of the first receivingterminals, for indicating the sequence of the first receiving terminalsfor sending the first BA respectively. And if there are more than twosecond receiving terminals, the sequence indication may further includeidentifiers of the second receiving terminals, for indicating thesequence of the second receiving terminals for sending the second BArespectively, wherein the identifier of each first receiving terminalmay include an MAC address of each first receiving terminal or an AID ofeach first receiving terminal. The identifier of each second receivingterminal may include an MAC address of each second receiving terminal oran AID of each second receiving terminal.

As shown in FIG. 8, it is a structural schematic diagram of a sequenceof each sending terminal and a sequence of each receiving terminal in asequence indication.

As shown in FIG. 9, it is a structural schematic diagram of the firstBAR or the second BAR, which is structurally similar to the first BA orthe second BA. Specifically, a position of the sequence indication inthe first BAR or the second BAR is similar to the position of thesequence indication in the first BA or the second BA, which will not berepeated redundantly herein.

In the present invention, an execution sequence of S402 and S403 is notlimited. Namely, in the present invention, S402 may be executed beforeS403, S403 may be executed before then S402, or S402 and S403 may alsobe simultaneously executed.

S404. each first receiving terminal respectively send the first BAcorresponding to the first BAR to the primary sending terminal, whereinthe first BA carries the sequence indication.

After each first receiving terminal respectively generates the first BA,each first receiving terminals respectively send, if the first BARrequesting the first BA from the primary sending terminal is received,the first BA corresponding to the first BAR to the primary sendingterminal.

It should be noted that, after sending the first BAR, the primarysending terminal may start to receive the first BA after a first presettime, wherein the first preset time may be SIFS. The SIFS provided bythe embodiment of the present invention may be defined as a receivingtime of the receiving terminal+a receiving/sending conversion time+asending time of a symbol.

Those of ordinary skill in the art may understand that, in the method ofcoordinated beamforming/interference alignment, after multiple sendingterminals obtain the right of use a channel by competition, the multiplesending terminals use the same channel to send respective data toreceiving terminals associated with the multiple sending terminalsrespectively, and the multiple sending terminals may obtain the BA sentby each receiving terminal through the shared channel. Namely, theprimary sending terminal and the secondary sending terminal maysimultaneously send the data of each receiving terminal to eachreceiving terminal associated with the same respectively, and theprimary sending terminal and the secondary sending terminal may alsosimultaneously obtain the BA sent by a certain receiving terminal.

S405. if the first BA indicates that the first data is correctlyreceived by each first receiving terminal, the primary sending terminalclears the first data cached in the primary sending terminal.Alternatively, if the first BA indicates that the first data is notcorrectly received by each first receiving terminal, the primary sendingterminal respectively retransmits first data which is not correctlyreceived and clears correctly received first data cached in the primarysending terminal.

After the primary sending terminal receives the first BA, the primarysending terminal may learn, according to the first BA, a receivingcondition of each first receiving terminal on the first data, namely thereceiving of the first data of each first receiving terminal succeeds orfails. If the first BA indicates that the first data is correctlyreceived by each first receiving terminal, the primary sending terminalclears the first data cached in the primary sending terminal. On thecontrary, if the first BA indicates that the first data is not correctlyreceived by each first receiving terminal, the primary sending terminalrespectively retransmits the first data which is not correctly receivedby each receiving terminal, and the primary sending terminal clears thefirst data which is correctly received by each receiving terminal, so asto guarantee the reliability of the transmission of the first data.

That the first data is not correctly received by each first receivingterminal, which is mentioned above, may include: none of each firstreceiving terminal correctly receive the first data sent by the primarysending terminal; or a part of first receiving terminals correctlyreceive the first data sent by the primary sending terminal, but a partof first receiving terminals do not correctly receive the first datasent by the primary sending terminal. In particular, the condition thata certain first receiving terminal does not correctly receive the firstdata may include: the first receiving terminal does not correctlyreceive all of the first data it corresponds to, or the first receivingterminal does not correctly receive a part of the first data itcorresponds to.

In the embodiment of the present invention, the primary sending terminalretransmits the first data which is not correctly received by each firstreceiving terminal, namely performs error recovery of the first data, toguarantee the reliability of the transmission of the first data.

S406. the secondary sending terminal obtains the first BA sent by eachfirst receiving terminal through the shared channel respectively, andobtains the sequence indication according to the first BA.

Since the primary sending terminal and the secondary sending terminalshare a channel, when each first receiving terminals send the first BAcorresponding to the first BAR to the primary sending terminal, thesecondary sending terminal may also obtain the first BA sent by theprimary sending terminal through the shared channel and may obtain thesequence indication according to the first BA.

S407. the secondary sending terminal respectively sends the second BARcorresponding to the second data to each second receiving terminalaccording to the sequence indication, wherein the second BAR carries thesequence indication.

After the secondary sending terminal obtains the sequence indicationcarried in the first BA, the secondary sending terminal may send thesecond BAR corresponding to the second data to each second receivingterminal according to the sequence indication respectively andsequentially, wherein the second BAR carries the sequence indication.

S408. each second receiving terminal respectively generates thecorresponding second BA according to the receiving condition thereof onthe second data.

After each second receiving terminal receives the second data, eachsecond receiving terminal respectively generates the correspondingsecond BA according to the receiving condition thereof on the seconddata.

In the present invention, the execution sequence of S407 and S408 is notlimited. Namely, in the present invention, S407 may be executed beforeS408, S408 may be executed before S407, or S407 and S408 may also besimultaneously executed.

S409. each second receiving terminal respectively sends the second BAcorresponding to the second BAR to the secondary sending terminal,wherein the second BA carries the sequence indication.

After each second receiving terminal generate the second BA, the secondreceiving terminals respectively send, if the second BAR requesting thesecond BA is received from the secondary sending terminal, the second BAcorresponding to the second BAR to the secondary sending terminal,wherein the second BA carries the sequence indication, which may be usedfor indicating a secondary sending terminal not sending the second BARto send the second BAR to each second receiving terminal it associateswith.

It should be noted that, after sending the second BAR, the secondarysending terminal starts to receive the second BA after the first presettime.

Further, the first preset time provided by the embodiment of the presentinvention starts to be calculated after the sending terminal sends theBAR. Namely, for the primary sending terminal, the above-mentioned firstpreset time starts to be calculated after the primary sending terminalsends the first BAR; and for the secondary sending terminal, the firstpreset time starts to be calculated after the secondary sending terminalsends the second BAR.

As shown in FIG. 10, it is a schematic diagram of error recovery incoordinated beamforming/interference alignment of multiple sendingterminals. The multiple sending terminals simultaneously send data ofeach receiving terminal respectively to each receiving terminal itassociates with and corresponds to. Then the primary sending terminalsends the BAR of each first receiving terminal it associates with toeach first receiving terminal at first, and thereby each first receivingterminal then respectively send back the first BA indicating a receivingcondition of data thereof to the primary sending terminal. Then eachsecondary sending terminal sequentially send, according to the presetsequence indication, the second BAR of each second receiving terminal itassociates with to each second receiving terminal it corresponds torespectively, and thereby the second receiving terminal thenrespectively send back the second BA indicating a receiving condition ofdata thereof to a corresponding secondary sending terminal.

S410. if the second BA indicates that the second data is correctlyreceived by each second receiving terminal, the secondary sendingterminal clears the second data cached in the secondary sendingterminal. Alternatively, if the second BA indicates that the second datais not correctly received by each second receiving terminal, thesecondary sending terminal respectively retransmits second data which isnot correctly received, and clears correctly received second data cachedin the secondary sending terminal.

After the secondary sending terminal receives the second BA, thesecondary sending terminal learns the receiving conditions of eachsecond receiving terminal on the second data according to the second BA,namely the receiving of the second data of each second receivingterminal succeeds or fails. If the second BA indicates that the seconddata is correctly received by each second receiving terminal, thesecondary sending terminal clears the data cached in the secondarysending terminal. On the contrary, if the second BA indicates that thesecond data is not correctly received by each second receiving terminal,the secondary sending terminal respectively retransmits the second datawhich is not correctly received by each second receiving terminal andclears the second data which is correctly received by each secondreceiving terminal and cached in the secondary sending terminal, so asto guarantee the reliability of the transmission of the second data.

That the second data is not correctly received by each second receivingterminal, which is mentioned above, may include: none of each secondreceiving terminal correctly receive the second data sent by thesecondary sending terminal; or a part of the second receiving terminalscorrectly receive the data sent by the secondary sending terminal, but apart of the second receiving terminals do not correctly receive thesecond data sent by the secondary sending terminal. In particular, thecondition that a certain second receiving terminal does not correctlyreceive the second data may include: the second receiving terminal doesnot correctly receive all of the second data it corresponds to, or thesecond receiving terminal does not correctly receive a part of thesecond data it corresponds to.

In the embodiment of the present invention, the secondary sendingterminal retransmits the second data which is correctly received by eachsecond receiving terminal, namely performs error recovery of the seconddata, to guarantee the reliability of the transmission of the seconddata.

It should be noted that, in the another communication method formultiple access points provided by the embodiment of the presentinvention, at first, the primary sending terminal sends the first BAR toeach first receiving terminal to request the receiving condition of eachfirst receiving terminal on the first data. After each first receivingterminal respectively send back the first BA, a secondary sendingterminal may sequentially send, according to the sequence indication inthe first BA, the second BAR to each second receiving terminal torequest the receiving condition of each second receiving terminal on thesecond data, until all the sending terminals at least request receivingterminals it associates with for one time.

S411. after the primary sending terminal respectively sends the firstBAR to each first receiving terminal, if the primary sending terminaldoes not receive the first BA corresponding to the first BAR after apreset time, the primary sending terminal resends the first BAR to firstreceiving terminals not sending back the first BA.

After the primary sending terminal sends the first BAR, the primarysending terminal resends, if the primary sending terminal does notreceive the first BA corresponding to the first BAR after the presettime, the first BAR to first receiving terminals not sending back thefirst BA.

It should be noted that, the preset time is PIFS, and PIFS is largerthan SIFS, wherein the PIFS provided by the embodiment of the presentinvention may be defined as SIFS+slot time.

Optionally, after the primary sending terminal receives the first BAsent by each first receiving terminal respectively, the primary sendingterminal sends, if the first BA indicates that the first data is notcorrectly received by each first receiving terminal, a first dataindication to each first receiving terminal not correctly receiving thefirst data, wherein the first data indication may be used for indicatingthe first data which is not correctly received by each first receivingterminal.

Optionally, the first data indication may be sent by being carried inthe first BAR, and it may also be sent by being carried in othermessages, which is not limited in the present invention.

Further, the above-mentioned preset time, which is similar to the firstpreset time, starts to be calculated after the sending terminal sendsthe BAR. The preset time in the above-mentioned S411 starts to becalculated after the primary sending terminal sends the first BAR.

S412. if the secondary sending terminal, after the secondary sendingterminal respectively sending the second BAR to each second receivingterminal, does not receive the second BA corresponding to the second BARafter a preset time, the secondary sending terminal resends the secondBAR to second receiving terminals not sending back the second BA.

If the secondary sending terminal, after the secondary sending terminalsending the second BAR, does not receive the second BA corresponding tothe second BAR after a preset time, the secondary sending terminalresends the second BAR to second receiving terminals not sending backthe second BA.

Optionally, after the secondary sending terminal receives the second BAsent by each second receiving terminal respectively, the secondarysending terminal sends, if the second BA indicates that the second datais not correctly received by each second receiving terminal, a seconddata indication to each second receiving terminal not correctlyreceiving the second data, wherein the second data indication may beused for indicating the second data which is not correctly received byeach second receiving terminal.

Optionally, the second data indication may be sent by being carried inthe second BAR, and it may also be sent by being carried in othermessages, which is not limited in the present invention.

It should be noted that, since the channel is shared, when each secondreceiving terminal send the second BA, the primary sending terminal mayalso obtain the second BA sent by each second receiving terminalrespectively. However, since the second BA and the sequence indicationcarried in the second BA are merely used for indicating other secondarysending terminals not sending the BAR to execute corresponding steps, aprocess of the primary sending terminal for receiving the second BA willnot be described in detail in the embodiment of the present invention.

The another communication method for multiple access points provided bythe embodiment of the present invention may support error recoveryduring simultaneous data transmission between multiple sending terminalsand multiple receiving terminals, thereby guaranteeing the reliabilityof data transmission and improving the throughput of the system.

According to the another communication method for multiple access pointsprovided by the embodiment of the present invention, after the primarysending terminal respectively sends the first data corresponding to eachfirst receiving terminal to each first receiving terminal and meanwhilethe secondary sending terminal respectively sends the second datacorresponding to each second receiving terminal to each second receivingterminal, the primary sending terminal respectively sends the first BARcorresponding to the first data to each first receiving terminal atfirst and receives the first BA sent by each first receiving terminalrespectively. If the first BA indicates that the first data is correctlyreceived by each first receiving terminal, the primary sending terminalclears the first data cached in the primary sending terminal, or if thefirst BA indicates that the first data is not correctly received by eachfirst receiving terminal, the primary sending terminal retransmits thefirst data which is not correctly received and clears the correctlyreceived data cached in the primary sending terminal. After thesecondary sending terminal obtains the first BA sent by each firstreceiving terminal through the shared channel respectively, thesecondary sending terminal respectively sends the second BARcorresponding to the second data to each second receiving terminalaccording to the sequence indication carried in the first BA andreceives the second BA corresponding to the second BAR, which is sent byeach second receiving terminal respectively. If the second BA indicatesthat the second data is correctly received by each second receivingterminal, the secondary sending terminal clears the second data cachedin the secondary sending terminal, or if the second BA indicates thatthe second data is not correctly received by each second receivingterminal, the secondary sending terminal respectively retransmits thesecond data which is not correctly received and clears the correctlyreceived second data cached in the secondary sending terminal. By meansof the solution, since the primary sending terminal can learn, accordingto the BA sent back by the each receiving terminal, data receivingcondition of the each receiving terminal, retransmit the data which arenot correctly received according to the indication of the BA and clearthe correctly received data cached in the primary sending terminal whenmultiple sending terminals and multiple receiving terminals transmitdata together, error recovery for data which fails to be received by theeach receiving terminal is therefore performed, and thereby thereliability of data transmission is guaranteed and the throughput ofsystem is improved.

Embodiment 3

As shown in FIG. 11, the embodiment of the present invention provides asending apparatus 1. It is applied to a wireless communication systemwhich obtains a channel based on a way of competition. The communicationsystem includes a primary sending terminal, at least one sendingapparatus 1 sharing a channel with the primary sending terminal and atleast one receiving terminal. Corresponding to a communication methodfor multiple access points provided by an embodiment of the presentinvention, the sending apparatus 1 may include:

a sending unit 10, configured to send data to the each receivingterminal with the primary sending terminal simultaneously through ashared channel, and retransmit, when the each receiving terminal doesnot correctly receive the data, data which is not correctly receivedwith the primary sending terminal simultaneously through the sharedchannel;

a storage unit 11, configured to cache the data;

an obtaining unit 12, configured to obtain a BA sent by the eachreceiving terminal through a shared channel respectively;

a clearing unit 13 configured to clear, if the BA indicates that thedata is correctly received by the each receiving terminal respectively,the data cached in the storage unit 11, or clear, if the BA indicatesthat the data is not correctly received by the each receiving terminal,correctly received data cached in the storage unit 11.

Optionally, as shown in FIG. 12, the sending apparatus 1 furtherincludes a receiving unit 14, and

the receiving unit 14 is configured to receive, before the clearing unit13 clears the correctly received data cached in the storage unit 11, afirst indication sent by the primary sending terminal, wherein the firstindication is used for indicating the data correctly received by theeach receiving terminal, which is obtained by the primary sendingterminal.

Optionally, the obtaining unit 12 is further configured to obtain asecond indication according to the BA, wherein the second indication isused for indicating data correctly received by the each receivingterminal, which is obtained by the sending apparatus; and the clearingunit 13 is specifically configured to calculate a union set of the dataindicated by the first indication and the data indicated by the secondindication, and clear, according to a result of the union setcalculation, data corresponding to the result, which is cached in thestorage unit 11.

According to the sending apparatus provided by the embodiment of thepresent invention, after the sending apparatus sends the datacorresponding to each receiving terminal to each receiving terminal, thesending apparatus obtains the BA sent by each receiving terminal throughthe shared channel respectively. If the BA indicates that the data iscorrectly received by each receiving terminal, the sending apparatusclears the data cached in the sending apparatus, or if the BA indicatesthat the data is not correctly received by each receiving terminal, thesending apparatus retransmits the data which is not correctly receivedand clears the correctly received data cached in the sending apparatus.By means of the solution, when the multiple sending terminals and themultiple receiving terminals transmit the data together, the sendingapparatus may learn, according to the BA sent back by each receivingterminal, a receiving condition of the data of each receiving terminal,retransmit the data which is not correctly received according to theindication of the BA and clear the correctly received data cached in thesending apparatus, so as to perform error recovery on the data failingto be received by each receiving terminal, namely to initiateretransmission, thereby guaranteeing the reliability of datatransmission and improving the throughput of the system.

As shown in FIG. 13, an embodiment of the present invention provides asending apparatus 2. It is applied to a wireless communication systemwhich obtains a channel based on a way of competition. The communicationsystem includes a primary sending terminal, at least one sendingapparatus 2 sharing a channel with the primary sending terminal, atleast one first receiving terminal associated with the primary sendingterminal and at least one second receiving terminal associated with thesending apparatus 2. Corresponding to another communication method formultiple access points provided by the embodiment of the presentinvention, the sending apparatus 2 may include:

a sending unit 20, configured to send second data corresponding to eachsecond receiving terminal to the each second receiving terminal with theprimary sending terminal synchronously through a shared channel;

an obtaining unit 21, configured to obtain a first block acknowledgementBA sent by the each first receiving terminal through the shared channelrespectively, and obtain a preset sequence indication according to thefirst BA, wherein the first BA carries the sequence indication, thesequence indication is used for indicating a sequence of the sendingapparatus 20 for sending a second block acknowledgement request BARcorresponding to the second data sent by the sending unit, and thesecond BAR carries the sequence indication;

the sending unit 20 is further configured to send, according to thesequence indication obtained by the obtaining unit 21, the second BAR tothe each second receiving terminal respectively, and retransmit, whenthe each second receiving terminal does not correctly receive the seconddata, second data which is not correctly received respectively;

a storage unit 22, configured to cache the second data;

a receiving unit 23, configured to receive second BA sent by the eachsecond receiving terminal respectively after the sending unit 20respectively sends the second BAR, wherein the second BA carries thesequence indication;

a clearing unit 24, configured to clear, if the second BA received bythe receiving unit 23 indicates that the second data is correctlyreceived by the each second receiving terminal, the second data cachedin the storage unit 22, or clear, if the second BA indicates that thesecond data is not correctly received by the each second receivingterminal, correctly received second data cached in the storage unit 22.

Optionally, the sending unit 20, after the sending unit 20 sends thesecond BAR corresponding to the second data to the each second receivingterminal respectively, is further configured to resend, if the receivingunit 23 does not receive the second BA corresponding to the second BARafter a preset time, the second BAR to a second receiving terminal whichdoes not send back the second BA.

Optionally, the sending unit 20, after the receiving unit 23 receivesthe second BA sent by the each second receiving terminal respectively,is further configured to send, if the second BA indicates that thesecond data is not correctly received by the each second receivingterminal, a second data indication to a second receiving terminal whichdoes not correctly receive the second data, wherein the second dataindication is used for indicating the second data which is not correctlyreceived by the each second receiving terminal.

According to the sending apparatus provided by the embodiment of thepresent invention, after the sending apparatus and the primary sendingterminal synchronously send the second data corresponding to each secondreceiving terminal to each second receiving terminal, the sendingapparatus obtains the first BA sent by each first receiving terminalthrough the shared channel respectively, and the sending apparatus sendsthe second BAR corresponding to the second data to each second receivingterminal according to the sequence indication carried in the first BAand receives the second BA corresponding to the second BAR and sent byeach second receiving terminal respectively. If the second BA indicatesthat the second is correctly received by each second receiving terminal,the second data cached in the sending apparatus is cleared, and if thesecond BA indicates that the second data is not correctly received byeach second receiving terminal, the second data which is not correctlyreceived is retransmitted and the correctly received second data cachedin the sending apparatus is cleared. By means of the solution, when themultiple sending terminals and the multiple receiving terminals transmitdata together, the sending apparatus may learn, according to the BA sentback by each receiving terminal, the receiving condition of data of eachreceiving terminal, retransmit the data which is not correctly receivedaccording to the indication of the BA and clear the correctly receiveddata cached in the sending apparatus, so as to perform error recovery onthe data failing to be received by each receiving terminal, therebyguaranteeing the reliability of data transmission and improving thethroughput of the system.

Embodiment 4

As shown in FIG. 14, an embodiment of the present invention provides abeam former 1. It is applied to a wireless communication system whichobtains a channel based on a way of competition. The communicationsystem includes a primary sending terminal, at least one beam former 1sharing a channel with the primary sending terminal and at least onereceiving terminal. Corresponding to the communication method formultiple access points provided by an embodiment of the presentinvention, the beam former 1 may include a transmitter 15, a receiver16, a processor 17 and a memory 18.

The transmitter 15 may be configured to send data to other communicationdevices. Particularly, when the beam former communicates with othercommunication devices, the transmitter 15 may send communication data tothe other communication devices.

The receiver 16 may be configured to receive data from the othercommunication devices. Particularly, when the beam former communicateswith the other communication devices, the receiver 16 may receive thecommunication data from the other communication devices.

The processor 17 is a control and processing center of the beam former.The processor control, through operating a software program stored inthe memory 18 and calling and processing data stored in the memory 18,the beam former to receive and send signals and achieve other functionsof the beam former.

The memory 18 may be configured to store software program and data, forenabling the processor 17 to operate the software program stored in thememory 18 to enable the beam former to receive and send signals andachieve other functions of the beam former.

The beam former provided by the embodiment of the present invention mayinclude a communication device in a wireless local area network such asa wireless router, wireless user equipment or the like.

Specifically, the transmitter 15 may be configured to simultaneouslysend data to each receiving terminal with the primary sending terminalthrough a shared channel, and simultaneously retransmit, when eachreceiving terminal does not correctly receive the data, the data whichis not correctly received with the primary sending terminal through theshared channel. The receiver 16 may be configured to obtain BA sent byeach receiving terminal through the shared channel respectively. Theprocessor 17 may be configured to clear, if the BA indicates that thedata is correctly received by each receiving terminal respectively, thedata cached in the memory 18, or clear, if the BA indicates that thedata is not correctly received by each receiving terminal, correctlyreceived data cached in the memory 18. The memory 18 may be configuredto store software codes of the data and software program for controllingthe beam former to complete the above-mentioned steps, so as to enablethe processor 17 to execute the above-mentioned software program andcall the above-mentioned software codes to complete the above-mentionedsteps.

Optionally, before the processor 17 clears the correctly received datacached in the memory 18, the receiver 16 is further configured toreceive a first indication sent by the primary sending terminal, whereinthe first indication is used for indicating the data correctly receivedby each receiving terminal which is obtained by the primary sendingterminal.

Optionally, the processor 17 is further configured to obtain a secondindication according to the BA, wherein the second indication is usedfor indicating the data correctly received by each receiving terminalwhich is obtained by the beam former. And the processor 17 isspecifically configured to calculate a union set of the data indicatedby the first indication and the data indicated by the second indication,and clear, according to a result of the union set calculation, the datacorresponding to the result, which is cached in the memory 18.

There is provided a beam former by the embodiment of the presentinvention. After the beam former sends the data corresponding to eachreceiving terminal to each receiving terminal, the beam former obtainsthe BA sent by each receiving terminal through the shared channelrespectively. If the BA indicates that the data is correctly received byeach receiving terminal, the beam former clears the data cached in thebeam former, or if the BA indicates that the data is not correctlyreceived by each receiving terminal, the beam former retransmits thedata which is not correctly received and clears the correctly receiveddata cached in the beam former. By means of the solution, when multiplesending terminals and multiple receiving terminals transmit the datatogether, the beam former may learn, according to the BA sent back byeach receiving terminal, a receiving condition of data of each receivingterminal, retransmit the data which is not correctly received accordingto the indication of the BA and clear the correctly received data cachedin the beam former, so as to perform error recovery on the data failingto be received by each receiving terminal, namely to initiateretransmission, thereby guaranteeing the reliability of the datatransmission and improving the throughput of the system.

As shown in FIG. 15, an embodiment of the present invention provides abeam former 2. It is applied to a wireless communication system whichobtains a channel based on a way of competition, the communicationsystem includes a primary sending terminal, at least one beam former 2sharing a channel with the primary sending terminal, at least one firstreceiving terminal associated with the primary sending terminal and atleast one second receiving terminal associated with the beam former 2.Corresponding to another communication method for multiple access pointsprovided by an embodiment of the present invention, the beam former 2may include a transmitter 25, a receiver 26, a processor 27 and a memory28.

The transmitter 25 may be configured to send data to other communicationdevices. Particularly, when the beam former communicates with othercommunication devices, the transmitter 25 may send communication data tothe other communication devices.

The receiver 26 may be configured to receive data from the othercommunication devices. Particularly, when the beam former communicateswith other communication devices, the receiver 26 may receive thecommunication data from the other communication devices.

The processor 27 is a control and processing center of the beam former,and is configured to control, through operating a software programstored in the memory 28 and calling and processing data stored in thememory 28, the beam former to receive and send signals and achieve otherfunctions of the beam former.

The memory 28 may be configured to store the software program and thedata, for enabling the processor 27 to operate the software programstored in the memory 28 to enable the beam former to receive and sendsignals and achieve the other functions of the beam former.

The beam former provided by the embodiment of the present invention mayinclude a communication device in a wireless local area network such asa wireless router, wireless user equipment or the like.

Specifically, the transmitter 25 may be configured to synchronously sendsecond data corresponding to each second receiving terminal to eachsecond receiving terminal with the primary sending terminal through ashared channel. The receiver 26 may be configured to obtain first BAsent by each first receiving terminal through the shared channelrespectively. The processor 27 may be configured to obtain a presetsequence indication according to the first BA, wherein the first BAcarries the sequence indication. The sequence indication is used forindicating the sequence of the beam former for sending second BARcorresponding to the second data sent by the transmitter 25, and thesecond BAR carries the sequence indication. The transmitter 25 may befurther configured to respectively send the second BAR to each secondreceiving terminal according to the sequence indication obtained by theprocessor 27, and respectively retransmit, when each second receivingterminal does not correctly receive the data, the second data which isnot correctly received. The receiver 26 may be further configured toreceive second BA sent by each second receiving terminal respectivelyafter the transmitter 25 respectively sends the second BAR, wherein thesecond BA carries the sequence indication. The memory 28 may beconfigured to store software codes of the second data, software codes ofthe first BA, software codes of the second BAR, software codes of thesecond BA and a software program used for controlling the beam former tocomplete the above-mentioned steps, for enabling the processor 27 tocomplete the above-mentioned steps by executing the above-mentionedsoftware program and calling the above-mentioned software codes.

Optionally, the transmitter 25 is further configured to resend, if thereceiver 26 does not receive the second BA corresponding to the secondBAR after a preset time, the second BAR to second receiving terminalsnot sending back the second BA after the transmitter 25 respectivelysends the second BAR corresponding to the second data to each secondreceiving terminal.

Optionally, the transmitter 25 is further configured to send, if thesecond BA indicates that the second data is not correctly received byeach second receiving terminal, a second data indication to each secondreceiving terminal not correctly receiving the second data after thereceiver 26 receives the second BA sent by each second receivingterminal respectively, wherein the second data indication is used forindicating the second data which is not correctly received by eachsecond receiving terminal.

There provided a beam former by the embodiment of the present invention.After the beam former and the primary sending terminal synchronouslysend the second data corresponding to each second receiving terminal toeach second receiving terminal, the beam former obtains the first BAsent by each first receiving terminal through the shared channelrespectively, and the beam former sends the second BAR corresponding tothe second data to each second receiving terminal according to thesequence indication carried in the first BA and receives the second BAcorresponding to the second BAR and sent by each second receivingterminal respectively. If the second BA indicates that the second datais correctly received by each second receiving terminal, the second datacached in the beam former is cleared, and if the second BA indicatesthat the second data is not correctly received by each second receivingterminal, the second data which is not correctly received isretransmitted and the correctly received second data cached in the beamformer is cleared. By means of the solution, when the multiple sendingterminals and the multiple receiving terminals transmit the datatogether, the beam former may learn, according to the BA sent back byeach receiving terminal, a receiving condition of data of each receivingterminal, retransmit the data which is not correctly received accordingto the indication of the BA and clear the correctly received data cachedin the beam former, so as to perform error recovery on the data failingto be received by each receiving terminal, thereby guaranteeing thereliability of data transmission and improving the throughput of thesystem.

Embodiment 5

As shown in FIG. 16, an embodiment of the present invention provides acommunication system. It is applied to a wireless communication scenariowhich obtains a channel based on a way of competition. The communicationsystem may include a primary beam former 3, at least one beam former 1and at least one beam receiver 4. It corresponds to a communicationmethod for multiple access points provided by an embodiment of thepresent invention, wherein the primary beam former 3 corresponds to aprimary sending terminal, the at least one beam former 1 respectivelycorresponds to at least one secondary sending terminal, and the at leastone beam receiver 4 respectively corresponds to at least one receivingterminal.

Specifically, the primary beam former is configured to respectively senddata corresponding to each beam receiver to each beam receiver;respectively send BAR corresponding to the data to each beam receiver;receive BA corresponding to the BAR which is sent by the beam receiverrespectively; and if the BA indicates that the data is correctlyreceived by each beam receiver, clear the data cached in the primarybeam former, and if the BA indicates that the data is not correctlyreceived by the beam receivers, retransmit data which is not correctlyreceived, and clear correctly received data cached in the primary beamformer.

The beam former is configured to simultaneously send the data to eachbeam receiver with the primary beam former through the shared channel.

The beam receiver is configured to receive the data sent by the primarybeam former and the beam former; receive the BAR corresponding to thedata, which is sent by the primary beam former; and send the BAcorresponding to the BAR to the primary beam former.

Optionally, the beam former is further configured to obtain the BA sentby each beam receiver through the shared channel respectively; and ifthe BA indicates that the data is correctly received by each beamreceiver respectively, clear the data cached in the beam former, or ifthe BA indicates that the data is not correctly received by each beamreceiver, simultaneously retransmit the data which is not correctlyreceived with the primary beam former through the shared channel, andclear the correctly received data cached in the beam former.

Optionally, after respectively sending the BAR corresponding to the datato each beam receiver, the primary beam former is further configured toresend, if not receiving the BA corresponding to the BAR after a presettime, the BAR to beam receivers not sending back the BA.

Optionally, after receiving the BA sent by each beam receiverrespectively, the primary beam former is further configured to send, ifthe BA indicates that the data is not correctly received by each beamreceiver, a data indication to each beam receiver not correctlyreceiving the data, wherein the data indication is used for indicatingthe data which is not correctly received by each beam receiver.

Optionally, there are more than two beam receivers, and the primary beamformer is specifically configured to respectively send the BAR to eachbeam receiver according to a preset sequence, wherein the presetsequence is that sending the BAR to each beam receiver belonging to asame BSS as the primary beam former at first and then sending the BAR toeach beam receiver not belonging to the same BSS as the primary beamformer.

Optionally, the primary beam former is specifically configured to:obtain a first indication according to the BA, wherein the firstindication is used for indicating the data correctly received by eachbeam receiver, which is obtained by the primary beam former; and clear,according to the first indication, the data corresponding to the firstindication, which is cached in the primary beam former.

Optionally, the primary beam former is further configured to send thefirst indication to the beam former.

Optionally, before clearing the correctly received data cached in thebeam former according to the BA, the beam former is further configuredto receive the first indication sent by the primary beam former.

Optionally, the beam former is specifically configured to: obtain asecond indication according to the BA, wherein the second indication isused for indicating the data correctly received by each beam receiver,which is obtained by the beam former; calculate a union set of the dataindicated by the first indication and the data indicated by the secondindication; clear, according to a result of union set calculation, thedata corresponding to the result and cached in the beam former.

There is provided a communication system by an embodiment of the presentinvention. After the primary beam former and the beam formersimultaneously send the data corresponding to each beam receiver to eachbeam receivers through the shared channel respectively, the primary beamformer respectively sends the BAR corresponding to the data to each beamreceiver. Moreover, the primary beam former and the beam former obtainthe BA corresponding to the BAR and sent by each beam receiverrespectively. If the BA indicates that the data is correctly received byeach beam receiver, the primary beam former and the beam former clearthe data cached therein respectively, and if the BA indicates that thedata is not correctly received by each beam receiver, the primary beamformer and the beam former retransmit the data which is not correctlyreceived and respectively clear the correctly received data cachedtherein. By means of the solution, when multiple beam formers andmultiple beam receivers transmit the data together, the multiple beamformers may learn, according to the BA sent back by each beam receiver,a receiving condition of data of each beam receiver, retransmit the datawhich is not correctly received according to the indication of the BAand clear the correctly received data cached therein respectively, so asto perform error recovery on the data failing to be received by the beamreceivers, namely to initiate retransmission, thereby guaranteeing thereliability of data transmission and improving the throughput of thesystem.

As shown in FIG. 17, an embodiment of the present invention furtherprovides another communication system. It is applied to a wirelesscommunication scenario which obtains a channel based on a way ofcompetition. The communication system may include a primary beam former5, at least one beam former 2, at least one first beam receiver 6associated with the primary beam former 5 and at least one second beamreceiver 7 associated with the at least one beam former 2. Itcorresponds to the another communication method for multiple accesspoints provided by an embodiment of the present invention, wherein theprimary beam former 5 corresponds to a primary sending terminal, the atleast one beam former 2 respectively corresponds to at least onesecondary sending terminal, the at least one first beam receiver 6respectively corresponds to at least one first receiving terminal, andthe at least one second beam receiver 7 respectively corresponds to atleast one second receiving terminal.

Specifically, the primary beam former is configured to: respectivelysend first data corresponding to each first beam receiver to each firstbeam receiver; respectively send first BAR corresponding to the firstdata to each first beam receiver; receive first BA corresponding to thefirst BAR and sent by each first beam receiver respectively; and if thefirst BA indicates that the first data is correctly received by eachfirst beam receiver, clear the first data cached in the primary beamformer, or if the first BA indicates that the first data is notcorrectly received by each first beam receiver, respectively retransmitthe first data which is not correctly received, and clear the correctlyreceived first data cached in the primary beam former, wherein the firstBAR and the first BA carry a preset sequence indication, the sequenceindication is used for indicating a sequence of the beam former forsending second BAR corresponding to second data, and the second BARcarries the sequence indication.

The beam former is configured to: synchronously send the second datacorresponding to each second beam receiver to each second beam receiverwith the primary beam former through a shared channel; obtain the firstBA sent by each first beam receiver through the shared channelrespectively, and obtain the sequence indication according to the firstBA; sequentially send the second BAR to each second beam receiveraccording to the sequence indication respectively; receive second BAcorresponding to the second BAR, which is sent by each second beamreceiver respectively, wherein the second BA carries the sequenceindication; and if the second BA indicates that the second data iscorrectly received by each second beam receiver, clear the second datacached in the beam former, or if the second BA indicates that the seconddata is not correctly received by each second beam receiver,respectively retransmit the second data which is not correctly received,and clear the correctly received second data cached in the beam former.

The first beam receiver is configured to: receive the first data and thefirst BAR sent by the primary beam former; and send the first BAcorresponding to the first BAR to the primary beam former.

The second beam receiver is configured to: receive the second data andthe second BAR sent by the beam former; and send the second BAcorresponding to the second BAR to the beam former.

Optionally, after respectively sending the first BAR corresponding tothe first data to each first beam receiver, the primary beam former isfurther configured to resend, if not receiving the first BAcorresponding to the first BAR after a preset time, the first BAR tofirst beam receivers not sending back the first BA.

Optionally, after receiving the first BA sent by each first beamreceiver respectively, the primary beam former is further configured tosend, if the first BA indicates that the first data is not correctlyreceived by each first beam receiver, a first data indication to eachfirst beam receiver not correctly receiving the first data, wherein thefirst data indication is used for indicating the first data which is notcorrectly received by each first beam receiver.

Optionally, after respectively sending the second BAR corresponding tothe second data to each second beam receiver respectively, the beamformer is further configured to resend, if not receiving the second BAcorresponding to the second BAR after the preset time, the second BAR toeach second beam receiver not sending back the second BA.

Optionally, after receiving the second BA sent by each second beamreceiver respectively, the beam former is further configured to send, ifthe second BA indicates that the second data is not correctly receivedby each second beam receiver, a second data indication to each secondbeam receiver not correctly receiving the second data, wherein thesecond data indication is used for indicating the second data which isnot correctly received by each second beam receiver.

Optionally, there are more than two beam formers, and the sequenceindication indicates that the beam formers belonging to the same BSS asthe primary beam former performs sending at first, and then the beamformers not belonging to the same BSS as the primary beam formerperforms sending, the sequence indication includes an identifier of theprimary beam former and an identifier of the beam former, wherein theidentifier of the primary beam former includes an MAC address or an AIDof the primary beam former, and the identifier of the beam formerrespectively include an MAC address or AID of each beam former.

Optionally, there are more than two first beam receivers and more thantwo second beam receivers. The sequence indication further includes anidentifier of each first beam receiver, for indicating the sequence ofeach first beam receiver for sending the first BA respectively. Thesequence indication further includes an identifier of each second beamreceiver, for indicating the sequence of each second beam receiver forsending the second BA respectively, wherein the identifier of each firstbeam receiver respectively include the MAC addresses or AIDs of eachfirst beam receiver, and the identifier of each second receivingterminal respectively include the MAC address or AID of the each secondbeam receiver.

There is provided another communication system by the embodiment of thepresent invention. After the primary beam former respectively sends thefirst data corresponding to each first beam receiver to each first beamreceiver, and meanwhile the beam former respectively sends the seconddata corresponding to each second beam receiver to each second beamreceiver, the primary beam former respectively sends first BARcorresponding to the first data to each first beam receiver at first andreceives the first BA sent by each first beam receiver respectively. Ifthe first BA indicates that the first data are correctly received byeach first beam receiver, the primary beam former clears the first datacached in the primary beam former, or if the first BA indicates that thefirst data is not correctly received by each first beam receiver. Theprimary beam former retransmits the first data which is not correctlyreceived and clears the correctly received first data cached in theprimary beam former. After the beam former obtains the first BA sent byeach first beam receiver through the shared channel respectively, thebeam former respectively sends second BAR corresponding to the seconddata to each second beam receiver according to the sequence indicationcarried in the first BA, and receives the second BA corresponding to thesecond BAR and sent by each second beam receiver respectively. Then, ifthe second BA indicates that the second data is correctly received byeach second beam receiver, the beam former clears the second data cachedin the beam former, or if the second BA indicates that the second datais not correctly received by the second beam receiver, the beam formerrespectively retransmits the second data which is not correctly receivedand clears the correctly received second data cached in the beam former.By means of the solution, when multiple beam formers and multiple beamreceivers transmit the data together, the multiple beam formers maylearn, according to the BA sent back by each beam receiver it associateswith respectively, a receiving condition of data of each beam receiver,retransmit the data which is not correctly received according to theindication of the BA and clear the correctly received data cachedtherein respectively, so as to perform error recovery on the datafailing to be received by each beam receiver, namely to initiateretransmission, thereby guaranteeing the reliability of datatransmission and improving the throughput of the system.

Those skilled in the art to which the present invention pertains mayclearly understand that, for convenience and simplicity of description,an illustration is merely given on the division of the above-mentionedfunctional modules, in practical application, the above-mentionedfunctions may be allocated to different functional modules according todemands for execution, namely the internal structure of the apparatus isdivided into different functional modules to complete all or a part offunctions described above. The specific working processes of the system,the apparatus and the units described above may refer to correspondingprocesses in the foregoing method embodiments, and will not be repeatedredundantly herein.

In the several embodiments provided in the present application, itshould be understood that, the disclosed system, apparatus and methodmay be implemented in other manners. For example, the apparatusembodiments described above are merely exemplary, e.g., the division ofthe modules or units is only a logic function division, other divisionmanners may exist in practical implementation, for example, a pluralityof units or components may be combined or integrated to another system,or some features may be omitted or not implemented. From another pointof view, the displayed or discussed mutual coupling or direct couplingor communication connection may be indirect coupling or communicationconnection of apparatuses or units through some interfaces, and may bein electrical, mechanical or other forms.

The units described as separate components may be separated physicallyor not, components displayed as units may be physical units or not,namely, may be located in one place, or may also be distributed on aplurality of network units. A part of or all of the units may beselected to implement the purposes of the solutions in the embodimentsaccording to actual demand.

In addition, the functional units in the embodiments of the presentinvention may be integrated in a processing unit, or the units singlyexist physically, or two or more units are integrated in one unit. Theabove-mentioned integrated unit may be both implemented in a hardwareform and may also be implemented in the form of a software functionalunit.

If the integrated unit is implemented in the form of the softwarefunctional unit and is sold or used as an independent product, it may bestored in a computer readable storage medium. Based on thisunderstanding, the technical solutions of the present inventionsubstantially, or the part contributing to the prior art, or all or apart of the technical solutions may be implemented in the form of asoftware product, the computer software product is stored in a storagemedium, and includes a plurality of instructions enabling a computerdevice (may be a personnel computer, a server, or a network device orthe like) or a processor (processor) to execute all or a part of thesteps of the methods in the embodiments of the present invention. Theforegoing storage medium includes a variety of media capable of storingprogram codes, such as a USB disk, a mobile hard disk, a read-onlymemory (ROM), a random access memory (RAM), a magnetic disk, an opticaldisk or the like.

The foregoing descriptions are merely specific implementations of thepresent invention, rather than limiting the protection scope of thepresent invention. Any skilled one who is familiar with this art couldreadily think of variations or substitutions within the disclosedtechnical scope of the present invention, and these variations orsubstitutions shall fall within the protection scope of the presentinvention. Accordingly, the protection scope of the claims shouldprevail over the protection scope of the present invention.

What is claimed is:
 1. A communication system, comprising a primarysending terminal, at least one secondary sending terminal sharing achannel with the primary sending terminal and at least one receivingterminal, wherein, the primary sending terminal is configured to: senddata corresponding to the at least one receiving terminal to the atleast one receiving terminal; send a block acknowledgement request (BAR)corresponding to the data to the at least one receiving terminal;receive a block acknowledgement (BA) corresponding to the BAR, which issent by the at least one receiving terminal; and clear the data cachedin the primary sending terminal, when the BA indicates that the data iscorrectly received by the at least one receiving terminal; the secondarysending terminal is configured to: send the data to the at least onereceiving terminal with the primary sending terminal simultaneouslythrough a shared channel; obtain the BA sent by the receiving terminalthrough the shared channel; and clear the data cached in the secondarysending terminal, when the BA indicates that the data is correctlyreceived by the receiving terminal; and the receiving terminal isconfigured to: receive the data sent by the primary sending terminal andthe secondary sending terminal; receive the BAR corresponding to thedata, which is sent by the primary sending terminal; and send the BAcorresponding to the BAR to the primary sending terminal, wherein thereare more than two receiving terminals, the primary sending terminal isspecifically configured to send, according to a preset sequence, the BARto the receiving terminals, wherein the preset sequence indicates thatthe BAR is sent to each receiving terminal belonging to a same basicservice set BSS as the primary sending terminal at first, and then theBAR is sent to each receiving terminal not belonging to the same BSS asthe primary sending terminal, wherein the primary sending terminal andthe at least one secondary sending terminal share the data sent to theat least one receiving terminal and channel information necessary forsending the data.
 2. The communication system of claim 1, wherein, thesecondary sending terminal is further configured to: if the BA indicatesthat the data is not correctly received by the at least one receivingterminal, retransmit data which is not correctly received with theprimary sending terminal simultaneously through the shared channelrespectively, and clear correctly received data cached in the secondarysending terminal.
 3. The communication system of claim 1, wherein, theprimary sending terminal, after sending the BAR corresponding to thedata to the at least one receiving terminal, is further configured toresend, if not receiving a BA corresponding to the BAR after a presettime, the BAR to a receiving terminal which does not send the BA back.4. The communication system of claim 1, wherein, the primary sendingterminal, after receiving the BA sent by the at least one receivingterminal, is further configured to send, if the BA indicates that thedata is not correctly received by the at least one receiving terminal, adata indication to each receiving terminal which does not correctlyreceive the data, wherein the data indication is used for indicating thedata which is not correctly received by the at least one receivingterminal.
 5. A communication system, comprising a primary sendingterminal, at least one secondary sending terminal sharing a channel withthe primary sending terminal and at least one receiving terminal,wherein, the primary sending terminal is configured to: send datacorresponding to the at least one receiving terminal to the at least onereceiving terminal; send a block acknowledgement request (BAR)corresponding to the data to the at least one receiving terminal;receive a block acknowledgement (BA) corresponding to the BAR, which issent by the at least one receiving terminal; and clear the data cachedin the primary sending terminal, when the BA indicates that the data iscorrectly received by the at least one receiving terminal; the secondarysending terminal is configured to: send the data to the at least onereceiving terminal with the primary sending terminal simultaneouslythrough a shared channel; obtain the BA sent by the receiving terminalthrough the shared channel; and clear the data cached in the secondarysending terminal, when the BA indicates that the data is correctlyreceived by the receiving terminal; and the receiving terminal isconfigured to: receive the data sent by the primary sending terminal andthe secondary sending terminal; receive the BAR corresponding to thedata, which is sent by the primary sending terminal; and send the BAcorresponding to the BAR to the primary sending terminal, wherein, theprimary sending terminal is specifically configured to: obtain a firstindication according to the BA, wherein the first indication is used forindicating the data correctly received by the at least one receivingterminal, which is obtained by the primary sending terminal; and clear,according to the first indication, the data corresponding to the firstindication, which is cached in the primary sending terminal, wherein,the secondary sending terminal is further configured to receive, beforeclearing correctly received data cached in the secondary sendingterminal according to the BA, the first indication sent by the primarysending terminal, wherein, the secondary sending terminal isspecifically configured to: obtain a second indication according to theBA, wherein the second indication is used for indicating the datacorrectly received by the at least one receiving terminal, which isobtained by the secondary sending terminal; calculate a union set of thedata indicated by the first indication and the data indicated by thesecond indication; and clear, according to a result of the union setcalculation, data corresponding to the result, which is cached in thesecondary sending terminal, wherein the primary sending terminal and theat least one secondary sending terminal share the data sent to the atleast one receiving terminal and channel information necessary forsending the data.
 6. A sending apparatus, applied to a wirelesscommunication system which obtains a channel based on a way ofcompetition, the communication system comprising a primary sendingterminal, at least one sending apparatus sharing a channel with theprimary sending terminal and at least one receiving terminal, whereinthe sending apparatus comprises: a non-transitory computer readablestorage medium; a transceiver; and a processor; wherein thenon-transitory computer readable storage medium comprises computerexecutable instructions, and when the instructions are executed: thetransceiver is configured to send data to the at least one receivingterminal through a shared channel, wherein the data is sent from theprimary sending terminal to the receiving terminal through the sharedchannel simultaneously; retransmit, when the at least one receivingterminal does not correctly receive the data, data which is notcorrectly received with the primary sending terminal simultaneouslythrough the shared channel; the processor is configured to cache thedata in a storage; obtain a block acknowledgement (BA) sent by the atleast one receiving terminal through a shared channel, wherein the BA issent in response to a block acknowledgement request (BAR) sent by theprimary sending terminal; and clear, if the BA indicates that the datais correctly received by the at least one receiving terminal, the datacached in the storage, wherein the transceiver is further configured toreceive, before the processor clears the correctly received data cachedin the storage, a first indication sent by the primary sending terminal,wherein the first indication is used for indicating the data correctlyreceived by the at least one receiving terminal, which is obtained bythe primary sending terminal, wherein, the transceiver is furtherconfigured to obtain a second indication according to the BA, whereinthe second indication is used for indicating data correctly received bythe at least one receiving terminal, which is obtained by the sendingapparatus; and the processor is specifically configured to calculate aunion set of the data indicated by the first indication and the dataindicated by the second indication, and clear, according to a result ofthe union set calculation, data corresponding to the result, which iscached in the storage, wherein the primary sending terminal and the atleast one sending apparatus share the data sent to the at least onereceiving terminal and channel information necessary for sending thedata.
 7. The sending apparatus of claim 6, wherein the processor isfurther configured to clear, if the BA indicates that the data is notcorrectly received by the at least one receiving terminal, correctlyreceived data cached in the storage.
 8. A communication method, appliedto a wireless communication system which obtains a channel based on away of competition, the communication system comprising a primarysending terminal, at least one secondary sending terminal sharing achannel with the primary sending terminal and at least one receivingterminal, wherein the method comprises: sending, by the secondarysending terminal, data to the at least one receiving terminal through ashared channel, wherein the data is sent from the primary sendingterminal to the receiving terminal through the shared channelsimultaneously; obtaining, by the secondary sending terminal, a blockacknowledgement (BA) sent by the at least one receiving terminal throughthe shared channel, wherein the BA is sent in response to a blockacknowledgement request (BAR) sent by the primary sending terminal; andif the BA indicates that the data is correctly received by the at leastone receiving terminal, clearing, by the secondary sending terminal, thedata cached in the secondary sending terminal, wherein before theclearing, by the secondary sending terminal, the data cached in thesecondary sending terminal, the method further comprises: receiving, bythe secondary sending terminal, a first indication sent by the primarysending terminal, wherein the first indication is used for indicatingthe data correctly received by the at least one receiving terminal,which is obtained by the primary sending terminal, wherein the clearing,by the secondary sending terminal, the data cached in the secondarysending terminal specifically comprises: obtaining, by the secondarysending terminal, a second indication according to the BA, wherein thesecond indication is used for indicating data correctly received by theat least one receiving terminal, which is obtained by the sendingapparatus; calculating, by the secondary sending terminal, a union setof the data indicated by the first indication and the data indicated bythe second indication; and clearing, by the secondary sending terminalaccording to a result of the union set calculation, the datacorresponding to the result, which is cached in the secondary sendingterminal, wherein the primary sending terminal and the at least onesecondary sending terminal share the data sent to the at least onereceiving terminal and channel information necessary for sending thedata.
 9. The communication method of claim 8, the method furthercomprising: if the BA indicates that the data is not correctly receivedby the at least one receiving terminal, retransmitting, by the secondarysending terminal, data which is not correctly received with the primarysending terminal simultaneously through the shared channel, andclearing, by the secondary sending terminal, correctly received datacached in the secondary sending terminal.
 10. The communication systemof claim 1, wherein, the primary sending terminal is further configuredto: retransmit data which is not correctly received and clear correctlyreceived data cached in the primary sending terminal, when the BAindicates that the data is not correctly received by the each receivingterminal.
 11. The communication system of claim 5, wherein, thesecondary sending terminal is further configured to: if the BA indicatesthat the data is not correctly received by the at least one receivingterminal, retransmit data which is not correctly received with theprimary sending terminal simultaneously through the shared channelrespectively, and clear correctly received data cached in the secondarysending terminal.
 12. The communication system of claim 5, wherein, theprimary sending terminal, after sending the BAR corresponding to thedata to the at least one receiving terminal, is further configured toresend, if not receiving a BA corresponding to the BAR after a presettime, the BAR to a receiving terminal which does not send the BA back.13. The communication system of claim 5, wherein, the primary sendingterminal, after receiving the BA sent by the at least one receivingterminal, is further configured to send, if the BA indicates that thedata is not correctly received by the at least one receiving terminal, adata indication to each receiving terminal which does not correctlyreceive the data, wherein the data indication is used for indicating thedata which is not correctly received by the at least one receivingterminal.